diff --git a/tests/NSubstitute.Analyzers.Tests.CSharp/DiagnosticAnalyzerTests/NonSubstitutableMemberAnalyzerTests/ThrowsAsExtensionMethodTests.cs b/tests/NSubstitute.Analyzers.Tests.CSharp/DiagnosticAnalyzerTests/NonSubstitutableMemberAnalyzerTests/ThrowsAsExtensionMethodTests.cs
index 837c1edb..315b1e5f 100644
--- a/tests/NSubstitute.Analyzers.Tests.CSharp/DiagnosticAnalyzerTests/NonSubstitutableMemberAnalyzerTests/ThrowsAsExtensionMethodTests.cs
+++ b/tests/NSubstitute.Analyzers.Tests.CSharp/DiagnosticAnalyzerTests/NonSubstitutableMemberAnalyzerTests/ThrowsAsExtensionMethodTests.cs
@@ -6,12 +6,13 @@
 
 namespace NSubstitute.Analyzers.Tests.CSharp.DiagnosticAnalyzerTests.NonSubstitutableMemberAnalyzerTests;
 
-[CombinatoryData("Throws", "ThrowsForAnyArgs")]
+[CombinatoryData("Throws", "ThrowsAsync", "ThrowsForAnyArgs", "ThrowsAsyncForAnyArgs")]
 public class ThrowsAsExtensionMethodTests : NonSubstitutableMemberDiagnosticVerifier
 {
     public override async Task ReportsDiagnostics_WhenSettingValueForNonVirtualMethod(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -19,9 +20,9 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public int Bar()
+        public Task<int> Bar()
         {{
-            return 2;
+            return Task.FromResult(1);
         }}
     }}
 
@@ -61,6 +62,7 @@ public void Test()
     public override async Task ReportsDiagnostics_WhenSettingValueForStaticMethod(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -68,9 +70,9 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public static int Bar()
+        public static Task<int> Bar()
         {{
-            return 2;
+            return Task.FromResult(2);
         }}
     }}
 
@@ -89,6 +91,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForVirtualMethod(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -96,9 +99,9 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public virtual int Bar()
+        public virtual Task<int> Bar()
         {{
-            return 2;
+            return Task.FromResult(2);
         }}
     }}
 
@@ -117,6 +120,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForNonSealedOverrideMethod(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -124,15 +128,15 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public virtual int Bar()
+        public virtual Task<int> Bar()
         {{
-            return 2;
+            return Task.FromResult(2);
         }}
     }}
 
     public class Foo2 : Foo
     {{
-        public override int Bar() => 1;
+        public override Task<int> Bar() => Task.FromResult(1);
     }}
 
     public class FooTests
@@ -150,6 +154,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenDataFlowAnalysisIsRequired(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -157,9 +162,9 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public virtual int Bar()
+        public virtual Task<int> Bar()
         {{
-            return 2;
+            return Task.FromResult(2);
         }}
     }}
 
@@ -179,6 +184,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForDelegate(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 using System;
@@ -189,7 +195,7 @@ public class FooTests
     {{
         public void Test()
         {{
-            var substitute = Substitute.For<Func<int>>();
+            var substitute = Substitute.For<Func<Task<int>>>();
             substitute().{method}(new Exception());
         }}
     }}
@@ -200,6 +206,7 @@ public void Test()
     public override async Task ReportsDiagnostics_WhenSettingValueForSealedOverrideMethod(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -207,15 +214,15 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public virtual int Bar()
+        public virtual Task<int> Bar()
         {{
-            return 2;
+            return Task.FromResult(2);
         }}
     }}
 
     public class Foo2 : Foo
     {{
-        public sealed override int Bar() => 1;
+        public sealed override Task<int> Bar() => Task.FromResult(1);
     }}
 
     public class FooTests
@@ -234,6 +241,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForAbstractMethod(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -241,7 +249,7 @@ namespace MyNamespace
 {{
     public abstract class Foo
     {{
-        public abstract int Bar();
+        public abstract Task<int> Bar();
     }}
 
     public class FooTests
@@ -260,6 +268,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForInterfaceMethod(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -267,7 +276,7 @@ namespace MyNamespace
 {{
     public interface IFoo
     {{
-        int Bar();
+        Task<int> Bar();
     }}
 
     public class FooTests
@@ -285,6 +294,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForInterfaceProperty(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -292,7 +302,7 @@ namespace MyNamespace
 {{
     public interface IFoo
     {{
-        int Bar {{ get; }}
+        Task<int> Bar {{ get; }}
     }}
 
     public class FooTests
@@ -310,6 +320,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForGenericInterfaceMethod(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -317,7 +328,7 @@ namespace MyNamespace
 {{
     public interface IFoo<T>
     {{
-        int Bar<T>();
+        Task<int> Bar<T>();
     }}
 
     public class FooTests
@@ -335,6 +346,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForAbstractProperty(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -342,7 +354,7 @@ namespace MyNamespace
 {{
     public abstract class Foo
     {{
-        public abstract int Bar {{ get; }}
+        public abstract Task<int> Bar {{ get; }}
     }}
 
     public class FooTests
@@ -361,6 +373,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForInterfaceIndexer(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -368,7 +381,7 @@ namespace MyNamespace
 {{
     public interface IFoo
     {{
-        int this[int i] {{ get; }}
+        Task<int> this[int i] {{ get; }}
     }}
 
     public class FooTests
@@ -386,6 +399,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForVirtualProperty(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -393,7 +407,7 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public virtual int Bar {{ get; }}
+        public virtual Task<int> Bar {{ get; }}
     }}
 
     public class FooTests
@@ -412,6 +426,7 @@ public void Test()
     public override async Task ReportsDiagnostics_WhenSettingValueForNonVirtualProperty(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -419,7 +434,7 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public int Bar {{ get; }}
+        public Task<int> Bar {{ get; }}
     }}
 
     public class FooTests
@@ -438,6 +453,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForVirtualIndexer(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -445,7 +461,7 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public virtual int this[int x] => 0;
+        public virtual Task<int> this[int x] => Task.FromResult(0);
     }}
 
     public class FooTests
@@ -463,6 +479,7 @@ public void Test()
     public override async Task ReportsDiagnostics_WhenSettingValueForNonVirtualIndexer(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -470,7 +487,7 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public int this[int x] => 0;
+        public Task<int> this[int x] => Task.FromResult(0);
     }}
 
     public class FooTests
@@ -490,13 +507,14 @@ public override async Task ReportsNoDiagnostics_WhenUsingUnfortunatelyNamedMetho
     {
         var source = $@"
 using System;
+using System.Threading.Tasks;
 namespace NSubstitute
 {{
     public class Foo
     {{
-        public int Bar()
+        public Task<int> Bar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
     }}
 
@@ -507,10 +525,20 @@ public static T Throws<T>(this object value, T ex) where T: Exception
             return default(T);
         }}
 
+        public static T ThrowsAsync<T>(this Task value, T ex) where T: Exception
+        {{
+            return default(T);
+        }}
+
         public static T ThrowsForAnyArgs<T>(this object value, T ex) where T: Exception
         {{
             return default(T);
         }}
+
+        public static T ThrowsAsyncForAnyArgs<T>(this Task value, T ex) where T: Exception
+        {{
+            return default(T);
+        }}
     }}
 
     public class FooTests
@@ -530,6 +558,7 @@ public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressi
         Settings = AnalyzersSettings.CreateWithSuppressions("P:MyNamespace.Foo.Bar", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -537,9 +566,9 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public int Bar {{ get; }}
+        public Task<int> Bar {{ get; }}
 
-        public int FooBar {{ get; }}
+        public Task<int> FooBar {{ get; }}
     }}
 
     public class FooTests
@@ -561,23 +590,24 @@ public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressi
         Settings = AnalyzersSettings.CreateWithSuppressions("P:MyNamespace.Foo`1.Bar", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
 namespace MyNamespace
 {{
-    public class Foo<T>
+    public class Foo<T> where T : Task
     {{
         public T Bar {{ get; }}
 
-        public int FooBar {{ get; }}
+        public Task<int> FooBar {{ get; }}
     }}
 
     public class FooTests
     {{
         public void Test()
         {{
-            var substitute = NSubstitute.Substitute.For<Foo<int>>();
+            var substitute = NSubstitute.Substitute.For<Foo<Task>>();
             substitute.Bar.{method}(new Exception());
             [|substitute.FooBar|].{method}(new Exception());
         }}
@@ -592,6 +622,7 @@ public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressi
         Settings = AnalyzersSettings.CreateWithSuppressions("M:MyNamespace.Foo.Bar(System.Int32,System.Int32)", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -599,14 +630,14 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public int Bar(int x)
+        public Task<int> Bar(int x)
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
 
-        public int Bar(int x, int y)
+        public Task<int> Bar(int x, int y)
         {{
-            return 2;
+            return Task.FromResult(2);
         }}
     }}
 
@@ -629,6 +660,7 @@ public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressi
         Settings = AnalyzersSettings.CreateWithSuppressions("M:MyNamespace.Foo.Bar``1(``0,``0)", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -636,14 +668,14 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public int Bar(int x)
+        public Task<int> Bar(int x)
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
 
-        public int Bar<T>(T x, T y)
+        public Task<int> Bar<T>(T x, T y)
         {{
-            return 2;
+            return Task.FromResult(2);
         }}
     }}
 
@@ -666,6 +698,7 @@ public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressi
         Settings = AnalyzersSettings.CreateWithSuppressions("P:MyNamespace.Foo.Item(System.Int32,System.Int32)", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -673,8 +706,8 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public int this[int x] => 0;
-        public int this[int x, int y] => 0;
+        public Task<int> this[int x] => Task.FromResult(0);
+        public Task<int> this[int x, int y] => Task.FromResult(0);
     }}
 
     public class FooTests
@@ -696,6 +729,7 @@ public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressi
         Settings = AnalyzersSettings.CreateWithSuppressions("P:MyNamespace.Foo`1.Item(`0,`0)", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -703,8 +737,8 @@ namespace MyNamespace
 {{
     public class Foo<T>
     {{
-        public int this[T x] => 0;
-        public int this[T x, T y] => 0;
+        public Task<int> this[T x] => Task.FromResult(0);
+        public Task<int> this[T x, T y] => Task.FromResult(0);
     }}
 
     public class FooTests
@@ -726,6 +760,7 @@ public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressi
         Settings = AnalyzersSettings.CreateWithSuppressions("T:MyNamespace.Foo", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -733,21 +768,21 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public int Bar {{ get; set; }}
-        public int this[int x] => 0;
-        public int FooBar()
+        public Task<int> Bar {{ get; set; }}
+        public Task<int> this[int x] => Task.FromResult(0);
+        public Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
     }}
 
     public class FooBarBar
     {{
-        public int Bar {{ get;set; }}
-        public int this[int x] => 0;
-        public int FooBar()
+        public Task<int> Bar {{ get;set; }}
+        public Task<int> this[int x] => Task.FromResult(0);
+        public Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
     }}
 
@@ -787,6 +822,7 @@ public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressi
         Settings = AnalyzersSettings.CreateWithSuppressions("T:MyNamespace.Foo`1", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -794,21 +830,21 @@ namespace MyNamespace
 {{
     public class Foo<T>
     {{
-        public int Bar {{ get; set; }}
-        public int this[int x] => 0;
-        public int FooBar()
+        public Task<int> Bar {{ get; set; }}
+        public Task<int> this[int x] => Task.FromResult(0);
+        public Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
     }}
 
     public class FooBarBar<T>
     {{
-        public int Bar {{ get;set; }}
-        public int this[int x] => 0;
-        public int FooBar()
+        public Task<int> Bar {{ get;set; }}
+        public Task<int> this[int x] => Task.FromResult(0);
+        public Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
     }}
 
@@ -848,6 +884,7 @@ public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressi
         Settings = AnalyzersSettings.CreateWithSuppressions("N:MyNamespace", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -855,11 +892,11 @@ namespace MyOtherNamespace
 {{
     public class FooBarBar
     {{
-        public int Bar {{ get; set; }}
-        public int this[int x] => 0;
-        public int FooBar()
+        public Task<int> Bar {{ get; set; }}
+        public Task<int> this[int x] => Task.FromResult(0);
+        public Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
     }}
 }}
@@ -869,11 +906,11 @@ namespace MyNamespace
     using MyOtherNamespace;
     public class Foo
     {{
-        public int Bar {{ get; set; }}
-        public int this[int x] => 0;
-        public int FooBar()
+        public Task<int> Bar {{ get; set; }}
+        public Task<int> this[int x] => Task.FromResult(0);
+        public Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
     }}
 
@@ -910,9 +947,10 @@ public void Test()
 
     public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressingExtensionMethod(string method)
     {
-        Settings = AnalyzersSettings.CreateWithSuppressions("M:MyNamespace.MyExtensions.GetBar(System.Object)~System.Int32", NonVirtualSetupSpecificationDescriptor.Id);
+        Settings = AnalyzersSettings.CreateWithSuppressions("M:MyNamespace.MyExtensions.GetBar(System.Object)~System.Threading.Tasks.Task{System.Int32}", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -933,20 +971,20 @@ public static class MyExtensions
     {{
         public static IBar Bar {{ get; set; }}
 
-        public static int GetBar(this object @object)
+        public static Task<int> GetBar(this object @object)
         {{
             return Bar.Foo(@object);
         }}
 
-        public static int GetFooBar(this object @object)
+        public static Task<int> GetFooBar(this object @object)
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
     }}
 
     public interface IBar
     {{
-        int Foo(object @obj);
+        Task<int> Foo(object @obj);
     }}
 }}";
 
@@ -956,6 +994,7 @@ public interface IBar
     public override async Task ReportsDiagnostics_WhenSettingValueForInternalVirtualMember_AndInternalsVisibleToNotApplied(string method, string call, string message)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -963,16 +1002,16 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        internal virtual int Bar {{ get; }}
+        internal virtual Task<int> Bar {{ get; }}
 
-        internal virtual int FooBar()
+        internal virtual Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
 
-        internal virtual int this[int x]
+        internal virtual Task<int> this[int x]
         {{
-            get {{ return 1; }}
+            get {{ return Task.FromResult(1); }}
         }}
     }}
 
@@ -992,6 +1031,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForInternalVirtualMember_AndInternalsVisibleToApplied(string method, string call)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 using System.Runtime.CompilerServices;
@@ -1003,16 +1043,16 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        internal virtual int Bar {{ get; }}
+        internal virtual Task<int> Bar {{ get; }}
 
-        internal virtual int FooBar()
+        internal virtual Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
 
-        internal virtual int this[int x]
+        internal virtual Task<int> this[int x]
         {{
-            get {{ return 1; }}
+            get {{ return Task.FromResult(1); }}
         }}
     }}
 
@@ -1032,6 +1072,7 @@ public void Test()
     public override async Task ReportsDiagnostics_WhenSettingValueForInternalVirtualMember_AndInternalsVisibleToAppliedToWrongAssembly(string method, string call, string message)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 using System.Runtime.CompilerServices;
@@ -1041,16 +1082,16 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        internal virtual int Bar {{ get; }}
+        internal virtual Task<int> Bar {{ get; }}
 
-        internal virtual int FooBar()
+        internal virtual Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
 
-        internal virtual int this[int x]
+        internal virtual Task<int> this[int x]
         {{
-            get {{ return 1; }}
+            get {{ return Task.FromResult(1); }}
         }}
     }}
 
@@ -1070,6 +1111,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForProtectedInternalVirtualMember(string method, string call)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -1077,16 +1119,16 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        protected internal virtual int Bar {{ get; }}
+        protected internal virtual Task<int> Bar {{ get; }}
 
-        protected internal virtual int FooBar()
+        protected internal virtual Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
 
-        protected internal virtual int this[int x]
+        protected internal virtual Task<int> this[int x]
         {{
-            get {{ return 1; }}
+            get {{ return Task.FromResult(1); }}
         }}
     }}
 
diff --git a/tests/NSubstitute.Analyzers.Tests.CSharp/DiagnosticAnalyzerTests/NonSubstitutableMemberAnalyzerTests/ThrowsAsExtensionMethodWithGenericTypeSpecifiedTests.cs b/tests/NSubstitute.Analyzers.Tests.CSharp/DiagnosticAnalyzerTests/NonSubstitutableMemberAnalyzerTests/ThrowsAsExtensionMethodWithGenericTypeSpecifiedTests.cs
index d7dbe5ee..018b8112 100644
--- a/tests/NSubstitute.Analyzers.Tests.CSharp/DiagnosticAnalyzerTests/NonSubstitutableMemberAnalyzerTests/ThrowsAsExtensionMethodWithGenericTypeSpecifiedTests.cs
+++ b/tests/NSubstitute.Analyzers.Tests.CSharp/DiagnosticAnalyzerTests/NonSubstitutableMemberAnalyzerTests/ThrowsAsExtensionMethodWithGenericTypeSpecifiedTests.cs
@@ -6,12 +6,13 @@
 
 namespace NSubstitute.Analyzers.Tests.CSharp.DiagnosticAnalyzerTests.NonSubstitutableMemberAnalyzerTests;
 
-[CombinatoryData("Throws<Exception>", "ThrowsForAnyArgs<Exception>")]
+[CombinatoryData("Throws<Exception>", "ThrowsAsync<Exception>", "ThrowsForAnyArgs<Exception>", "ThrowsAsyncForAnyArgs<Exception>")]
 public class ThrowsAsExtensionMethodWithGenericTypeSpecifiedTests : NonSubstitutableMemberDiagnosticVerifier
 {
     public override async Task ReportsDiagnostics_WhenSettingValueForNonVirtualMethod(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -19,9 +20,9 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public int Bar()
+        public Task<int> Bar()
         {{
-            return 2;
+            return Task.FromResult(1);
         }}
     }}
 
@@ -61,6 +62,7 @@ public void Test()
     public override async Task ReportsDiagnostics_WhenSettingValueForStaticMethod(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -68,9 +70,9 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public static int Bar()
+        public static Task<int> Bar()
         {{
-            return 2;
+            return Task.FromResult(2);
         }}
     }}
 
@@ -89,6 +91,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForVirtualMethod(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -96,9 +99,9 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public virtual int Bar()
+        public virtual Task<int> Bar()
         {{
-            return 2;
+            return Task.FromResult(2);
         }}
     }}
 
@@ -117,6 +120,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForNonSealedOverrideMethod(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -124,15 +128,15 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public virtual int Bar()
+        public virtual Task<int> Bar()
         {{
-            return 2;
+            return Task.FromResult(2);
         }}
     }}
 
     public class Foo2 : Foo
     {{
-        public override int Bar() => 1;
+        public override Task<int> Bar() => Task.FromResult(1);
     }}
 
     public class FooTests
@@ -150,6 +154,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenDataFlowAnalysisIsRequired(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -157,9 +162,9 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public virtual int Bar()
+        public virtual Task<int> Bar()
         {{
-            return 2;
+            return Task.FromResult(2);
         }}
     }}
 
@@ -179,6 +184,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForDelegate(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 using System;
@@ -189,7 +195,7 @@ public class FooTests
     {{
         public void Test()
         {{
-            var substitute = Substitute.For<Func<int>>();
+            var substitute = Substitute.For<Func<Task<int>>>();
             substitute().{method}();
         }}
     }}
@@ -200,6 +206,7 @@ public void Test()
     public override async Task ReportsDiagnostics_WhenSettingValueForSealedOverrideMethod(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -207,15 +214,15 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public virtual int Bar()
+        public virtual Task<int> Bar()
         {{
-            return 2;
+            return Task.FromResult(2);
         }}
     }}
 
     public class Foo2 : Foo
     {{
-        public sealed override int Bar() => 1;
+        public sealed override Task<int> Bar() => Task.FromResult(1);
     }}
 
     public class FooTests
@@ -234,6 +241,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForAbstractMethod(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -241,7 +249,7 @@ namespace MyNamespace
 {{
     public abstract class Foo
     {{
-        public abstract int Bar();
+        public abstract Task<int> Bar();
     }}
 
     public class FooTests
@@ -260,6 +268,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForInterfaceMethod(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -267,7 +276,7 @@ namespace MyNamespace
 {{
     public interface IFoo
     {{
-        int Bar();
+        Task<int> Bar();
     }}
 
     public class FooTests
@@ -285,6 +294,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForInterfaceProperty(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -292,7 +302,7 @@ namespace MyNamespace
 {{
     public interface IFoo
     {{
-        int Bar {{ get; }}
+        Task<int> Bar {{ get; }}
     }}
 
     public class FooTests
@@ -310,6 +320,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForGenericInterfaceMethod(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -317,7 +328,7 @@ namespace MyNamespace
 {{
     public interface IFoo<T>
     {{
-        int Bar<T>();
+        Task<int> Bar<T>();
     }}
 
     public class FooTests
@@ -335,6 +346,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForAbstractProperty(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -342,7 +354,7 @@ namespace MyNamespace
 {{
     public abstract class Foo
     {{
-        public abstract int Bar {{ get; }}
+        public abstract Task<int> Bar {{ get; }}
     }}
 
     public class FooTests
@@ -361,6 +373,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForInterfaceIndexer(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -368,7 +381,7 @@ namespace MyNamespace
 {{
     public interface IFoo
     {{
-        int this[int i] {{ get; }}
+        Task<int> this[int i] {{ get; }}
     }}
 
     public class FooTests
@@ -386,6 +399,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForVirtualProperty(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -393,7 +407,7 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public virtual int Bar {{ get; }}
+        public virtual Task<int> Bar {{ get; }}
     }}
 
     public class FooTests
@@ -412,6 +426,7 @@ public void Test()
     public override async Task ReportsDiagnostics_WhenSettingValueForNonVirtualProperty(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -419,7 +434,7 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public int Bar {{ get; }}
+        public Task<int> Bar {{ get; }}
     }}
 
     public class FooTests
@@ -438,6 +453,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForVirtualIndexer(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -445,7 +461,7 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public virtual int this[int x] => 0;
+        public virtual Task<int> this[int x] => Task.FromResult(0);
     }}
 
     public class FooTests
@@ -463,6 +479,7 @@ public void Test()
     public override async Task ReportsDiagnostics_WhenSettingValueForNonVirtualIndexer(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -470,7 +487,7 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public int this[int x] => 0;
+        public Task<int> this[int x] => Task.FromResult(0);
     }}
 
     public class FooTests
@@ -490,13 +507,14 @@ public override async Task ReportsNoDiagnostics_WhenUsingUnfortunatelyNamedMetho
     {
         var source = $@"
 using System;
+using System.Threading.Tasks;
 namespace NSubstitute
 {{
     public class Foo
     {{
-        public int Bar()
+        public Task<int> Bar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
     }}
 
@@ -507,10 +525,20 @@ public static T Throws<T>(this object value) where T: Exception
             return default(T);
         }}
 
+        public static T ThrowsAsync<T>(this Task value) where T: Exception
+        {{
+            return default(T);
+        }}
+
         public static T ThrowsForAnyArgs<T>(this object value) where T: Exception
         {{
             return default(T);
         }}
+
+        public static T ThrowsAsyncForAnyArgs<T>(this Task value) where T: Exception
+        {{
+            return default(T);
+        }}
     }}
 
     public class FooTests
@@ -530,6 +558,7 @@ public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressi
         Settings = AnalyzersSettings.CreateWithSuppressions("P:MyNamespace.Foo.Bar", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -537,9 +566,9 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public int Bar {{ get; }}
+        public Task<int> Bar {{ get; }}
 
-        public int FooBar {{ get; }}
+        public Task<int> FooBar {{ get; }}
     }}
 
     public class FooTests
@@ -561,23 +590,24 @@ public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressi
         Settings = AnalyzersSettings.CreateWithSuppressions("P:MyNamespace.Foo`1.Bar", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
 namespace MyNamespace
 {{
-    public class Foo<T>
+    public class Foo<T> where T : Task
     {{
         public T Bar {{ get; }}
 
-        public int FooBar {{ get; }}
+        public Task<int> FooBar {{ get; }}
     }}
 
     public class FooTests
     {{
         public void Test()
         {{
-            var substitute = NSubstitute.Substitute.For<Foo<int>>();
+            var substitute = NSubstitute.Substitute.For<Foo<Task<int>>>();
             substitute.Bar.{method}();
             [|substitute.FooBar|].{method}();
         }}
@@ -592,6 +622,7 @@ public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressi
         Settings = AnalyzersSettings.CreateWithSuppressions("M:MyNamespace.Foo.Bar(System.Int32,System.Int32)", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -599,14 +630,14 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public int Bar(int x)
+        public Task<int> Bar(int x)
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
 
-        public int Bar(int x, int y)
+        public Task<int> Bar(int x, int y)
         {{
-            return 2;
+            return Task.FromResult(2);
         }}
     }}
 
@@ -629,6 +660,7 @@ public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressi
         Settings = AnalyzersSettings.CreateWithSuppressions("M:MyNamespace.Foo.Bar``1(``0,``0)", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -636,14 +668,14 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public int Bar(int x)
+        public Task<int> Bar(int x)
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
 
-        public int Bar<T>(T x, T y)
+        public Task<int> Bar<T>(T x, T y)
         {{
-            return 2;
+            return Task.FromResult(2);
         }}
     }}
 
@@ -666,6 +698,7 @@ public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressi
         Settings = AnalyzersSettings.CreateWithSuppressions("P:MyNamespace.Foo.Item(System.Int32,System.Int32)", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -673,8 +706,8 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public int this[int x] => 0;
-        public int this[int x, int y] => 0;
+        public Task<int> this[int x] => Task.FromResult(0);
+        public Task<int> this[int x, int y] => Task.FromResult(0);
     }}
 
     public class FooTests
@@ -696,6 +729,7 @@ public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressi
         Settings = AnalyzersSettings.CreateWithSuppressions("P:MyNamespace.Foo`1.Item(`0,`0)", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -703,8 +737,8 @@ namespace MyNamespace
 {{
     public class Foo<T>
     {{
-        public int this[T x] => 0;
-        public int this[T x, T y] => 0;
+        public Task<int> this[T x] => Task.FromResult(0);
+        public Task<int> this[T x, T y] => Task.FromResult(0);
     }}
 
     public class FooTests
@@ -726,6 +760,7 @@ public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressi
         Settings = AnalyzersSettings.CreateWithSuppressions("T:MyNamespace.Foo", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -733,21 +768,21 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public int Bar {{ get; set; }}
-        public int this[int x] => 0;
-        public int FooBar()
+        public Task<int> Bar {{ get; set; }}
+        public Task<int> this[int x] => Task.FromResult(0);
+        public Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
     }}
 
     public class FooBarBar
     {{
-        public int Bar {{ get;set; }}
-        public int this[int x] => 0;
-        public int FooBar()
+        public Task<int> Bar {{ get;set; }}
+        public Task<int> this[int x] => Task.FromResult(0);
+        public Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
     }}
 
@@ -787,6 +822,7 @@ public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressi
         Settings = AnalyzersSettings.CreateWithSuppressions("T:MyNamespace.Foo`1", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -794,21 +830,21 @@ namespace MyNamespace
 {{
     public class Foo<T>
     {{
-        public int Bar {{ get; set; }}
-        public int this[int x] => 0;
-        public int FooBar()
+        public Task<int> Bar {{ get; set; }}
+        public Task<int> this[int x] => Task.FromResult(0);
+        public Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
     }}
 
     public class FooBarBar<T>
     {{
-        public int Bar {{ get;set; }}
-        public int this[int x] => 0;
-        public int FooBar()
+        public Task<int> Bar {{ get;set; }}
+        public Task<int> this[int x] => Task.FromResult(0);
+        public Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
     }}
 
@@ -848,6 +884,7 @@ public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressi
         Settings = AnalyzersSettings.CreateWithSuppressions("N:MyNamespace", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -855,11 +892,11 @@ namespace MyOtherNamespace
 {{
     public class FooBarBar
     {{
-        public int Bar {{ get; set; }}
-        public int this[int x] => 0;
-        public int FooBar()
+        public Task<int> Bar {{ get; set; }}
+        public Task<int> this[int x] => Task.FromResult(0);
+        public Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
     }}
 }}
@@ -869,11 +906,11 @@ namespace MyNamespace
     using MyOtherNamespace;
     public class Foo
     {{
-        public int Bar {{ get; set; }}
-        public int this[int x] => 0;
-        public int FooBar()
+        public Task<int> Bar {{ get; set; }}
+        public Task<int> this[int x] => Task.FromResult(0);
+        public Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
     }}
 
@@ -910,9 +947,10 @@ public void Test()
 
     public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressingExtensionMethod(string method)
     {
-        Settings = AnalyzersSettings.CreateWithSuppressions("M:MyNamespace.MyExtensions.GetBar(System.Object)~System.Int32", NonVirtualSetupSpecificationDescriptor.Id);
+        Settings = AnalyzersSettings.CreateWithSuppressions("M:MyNamespace.MyExtensions.GetBar(System.Object)~System.Threading.Tasks.Task{System.Int32}", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -933,20 +971,20 @@ public static class MyExtensions
     {{
         public static IBar Bar {{ get; set; }}
 
-        public static int GetBar(this object @object)
+        public static Task<int> GetBar(this object @object)
         {{
             return Bar.Foo(@object);
         }}
 
-        public static int GetFooBar(this object @object)
+        public static Task<int> GetFooBar(this object @object)
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
     }}
 
     public interface IBar
     {{
-        int Foo(object @obj);
+        Task<int> Foo(object @obj);
     }}
 }}";
 
@@ -956,6 +994,7 @@ public interface IBar
     public override async Task ReportsDiagnostics_WhenSettingValueForInternalVirtualMember_AndInternalsVisibleToNotApplied(string method, string call, string message)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -963,16 +1002,16 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        internal virtual int Bar {{ get; }}
+        internal virtual Task<int> Bar {{ get; }}
 
-        internal virtual int FooBar()
+        internal virtual Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
 
-        internal virtual int this[int x]
+        internal virtual Task<int> this[int x]
         {{
-            get {{ return 1; }}
+            get {{ return Task.FromResult(1); }}
         }}
     }}
 
@@ -992,6 +1031,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForInternalVirtualMember_AndInternalsVisibleToApplied(string method, string call)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 using System.Runtime.CompilerServices;
@@ -1003,16 +1043,16 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        internal virtual int Bar {{ get; }}
+        internal virtual Task<int> Bar {{ get; }}
 
-        internal virtual int FooBar()
+        internal virtual Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
 
-        internal virtual int this[int x]
+        internal virtual Task<int> this[int x]
         {{
-            get {{ return 1; }}
+            get {{ return Task.FromResult(1); }}
         }}
     }}
 
@@ -1032,6 +1072,7 @@ public void Test()
     public override async Task ReportsDiagnostics_WhenSettingValueForInternalVirtualMember_AndInternalsVisibleToAppliedToWrongAssembly(string method, string call, string message)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 using System.Runtime.CompilerServices;
@@ -1041,16 +1082,16 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        internal virtual int Bar {{ get; }}
+        internal virtual Task<int> Bar {{ get; }}
 
-        internal virtual int FooBar()
+        internal virtual Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
 
-        internal virtual int this[int x]
+        internal virtual Task<int> this[int x]
         {{
-            get {{ return 1; }}
+            get {{ return Task.FromResult(1); }}
         }}
     }}
 
@@ -1070,6 +1111,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForProtectedInternalVirtualMember(string method, string call)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -1077,16 +1119,16 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        protected internal virtual int Bar {{ get; }}
+        protected internal virtual Task<int> Bar {{ get; }}
 
-        protected internal virtual int FooBar()
+        protected internal virtual Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
 
-        protected internal virtual int this[int x]
+        protected internal virtual Task<int> this[int x]
         {{
-            get {{ return 1; }}
+            get {{ return Task.FromResult(1); }}
         }}
     }}
 
diff --git a/tests/NSubstitute.Analyzers.Tests.CSharp/DiagnosticAnalyzerTests/NonSubstitutableMemberAnalyzerTests/ThrowsAsOrdinaryMethodTests.cs b/tests/NSubstitute.Analyzers.Tests.CSharp/DiagnosticAnalyzerTests/NonSubstitutableMemberAnalyzerTests/ThrowsAsOrdinaryMethodTests.cs
index f25e455b..54b9a02f 100644
--- a/tests/NSubstitute.Analyzers.Tests.CSharp/DiagnosticAnalyzerTests/NonSubstitutableMemberAnalyzerTests/ThrowsAsOrdinaryMethodTests.cs
+++ b/tests/NSubstitute.Analyzers.Tests.CSharp/DiagnosticAnalyzerTests/NonSubstitutableMemberAnalyzerTests/ThrowsAsOrdinaryMethodTests.cs
@@ -1,4 +1,4 @@
-using System.Linq;
+using System.Linq;
 using System.Threading.Tasks;
 using NSubstitute.Analyzers.Shared.Settings;
 using NSubstitute.Analyzers.Tests.Shared.Extensibility;
@@ -6,12 +6,17 @@
 
 namespace NSubstitute.Analyzers.Tests.CSharp.DiagnosticAnalyzerTests.NonSubstitutableMemberAnalyzerTests;
 
-[CombinatoryData("ExceptionExtensions.Throws", "ExceptionExtensions.ThrowsForAnyArgs")]
+[CombinatoryData(
+    "ExceptionExtensions.Throws",
+    "ExceptionExtensions.ThrowsAsync",
+    "ExceptionExtensions.ThrowsForAnyArgs",
+    "ExceptionExtensions.ThrowsAsyncForAnyArgs")]
 public class ThrowsAsOrdinaryMethodTests : NonSubstitutableMemberDiagnosticVerifier
 {
     public override async Task ReportsDiagnostics_WhenSettingValueForNonVirtualMethod(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -19,9 +24,9 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public int Bar()
+        public Task<int> Bar()
         {{
-            return 2;
+            return Task.FromResult(1);
         }}
     }}
 
@@ -64,6 +69,7 @@ public void Test()
     public override async Task ReportsDiagnostics_WhenSettingValueForStaticMethod(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -71,9 +77,9 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public static int Bar()
+        public static Task<int> Bar()
         {{
-            return 2;
+            return Task.FromResult(2);
         }}
     }}
 
@@ -94,6 +100,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForVirtualMethod(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -101,9 +108,9 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public virtual int Bar()
+        public virtual Task<int> Bar()
         {{
-            return 2;
+            return Task.FromResult(2);
         }}
     }}
 
@@ -124,6 +131,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForNonSealedOverrideMethod(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -131,15 +139,15 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public virtual int Bar()
+        public virtual Task<int> Bar()
         {{
-            return 2;
+            return Task.FromResult(2);
         }}
     }}
 
     public class Foo2 : Foo
     {{
-        public override int Bar() => 1;
+        public override Task<int> Bar() => Task.FromResult(1);
     }}
 
     public class FooTests
@@ -159,6 +167,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenDataFlowAnalysisIsRequired(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -166,9 +175,9 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public virtual int Bar()
+        public virtual Task<int> Bar()
         {{
-            return 2;
+            return Task.FromResult(2);
         }}
     }}
 
@@ -190,6 +199,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForDelegate(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 using System;
@@ -200,7 +210,7 @@ public class FooTests
     {{
         public void Test()
         {{
-            var substitute = Substitute.For<Func<int>>();
+            var substitute = Substitute.For<Func<Task<int>>>();
             {method}(substitute(), new Exception());
             {method}(value: substitute(), ex: new Exception());
             {method}(ex: new Exception(), value: substitute());
@@ -213,6 +223,7 @@ public void Test()
     public override async Task ReportsDiagnostics_WhenSettingValueForSealedOverrideMethod(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -220,15 +231,15 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public virtual int Bar()
+        public virtual Task<int> Bar()
         {{
-            return 2;
+            return Task.FromResult(2);
         }}
     }}
 
     public class Foo2 : Foo
     {{
-        public sealed override int Bar() => 1;
+        public sealed override Task<int> Bar() => Task.FromResult(1);
     }}
 
     public class FooTests
@@ -249,6 +260,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForAbstractMethod(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -256,7 +268,7 @@ namespace MyNamespace
 {{
     public abstract class Foo
     {{
-        public abstract int Bar();
+        public abstract Task<int> Bar();
     }}
 
     public class FooTests
@@ -277,6 +289,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForInterfaceMethod(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -284,7 +297,7 @@ namespace MyNamespace
 {{
     public interface IFoo
     {{
-        int Bar();
+        Task<int> Bar();
     }}
 
     public class FooTests
@@ -304,6 +317,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForInterfaceProperty(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -311,7 +325,7 @@ namespace MyNamespace
 {{
     public interface IFoo
     {{
-        int Bar {{ get; }}
+        Task<int> Bar {{ get; }}
     }}
 
     public class FooTests
@@ -331,6 +345,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForGenericInterfaceMethod(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -338,7 +353,7 @@ namespace MyNamespace
 {{
     public interface IFoo<T>
     {{
-        int Bar<T>();
+        Task<int> Bar<T>();
     }}
 
     public class FooTests
@@ -358,6 +373,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForAbstractProperty(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -365,7 +381,7 @@ namespace MyNamespace
 {{
     public abstract class Foo
     {{
-        public abstract int Bar {{ get; }}
+        public abstract Task<int> Bar {{ get; }}
     }}
 
     public class FooTests
@@ -386,6 +402,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForInterfaceIndexer(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -393,7 +410,7 @@ namespace MyNamespace
 {{
     public interface IFoo
     {{
-        int this[int i] {{ get; }}
+        Task<int> this[int i] {{ get; }}
     }}
 
     public class FooTests
@@ -413,6 +430,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForVirtualProperty(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -420,7 +438,7 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public virtual int Bar {{ get; }}
+        public virtual Task<int> Bar {{ get; }}
     }}
 
     public class FooTests
@@ -441,6 +459,7 @@ public void Test()
     public override async Task ReportsDiagnostics_WhenSettingValueForNonVirtualProperty(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -448,7 +467,7 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public int Bar {{ get; }}
+        public Task<int> Bar {{ get; }}
     }}
 
     public class FooTests
@@ -469,6 +488,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForVirtualIndexer(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -476,7 +496,7 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public virtual int this[int x] => 0;
+        public virtual Task<int> this[int x] => Task.FromResult(0);
     }}
 
     public class FooTests
@@ -496,6 +516,7 @@ public void Test()
     public override async Task ReportsDiagnostics_WhenSettingValueForNonVirtualIndexer(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -503,7 +524,7 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public int this[int x] => 0;
+        public Task<int> this[int x] => Task.FromResult(0);
     }}
 
     public class FooTests
@@ -525,13 +546,14 @@ public override async Task ReportsNoDiagnostics_WhenUsingUnfortunatelyNamedMetho
     {
         var source = $@"
 using System;
+using System.Threading.Tasks;
 namespace NSubstitute
 {{
     public class Foo
     {{
-        public int Bar()
+        public Task<int> Bar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
     }}
 
@@ -542,10 +564,20 @@ public static T Throws<T>(this object value, T ex) where T: Exception
             return default(T);
         }}
 
+        public static T ThrowsAsync<T>(this Task value, T ex) where T: Exception
+        {{
+            return default(T);
+        }}
+
         public static T ThrowsForAnyArgs<T>(this object value, T ex) where T: Exception
         {{
             return default(T);
         }}
+
+        public static T ThrowsAsyncForAnyArgs<T>(this Task value, T ex) where T: Exception
+        {{
+            return default(T);
+        }}
     }}
 
     public class FooTests
@@ -567,6 +599,7 @@ public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressi
         Settings = AnalyzersSettings.CreateWithSuppressions("P:MyNamespace.Foo.Bar", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -574,9 +607,9 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public int Bar {{ get; }}
+        public Task<int> Bar {{ get; }}
 
-        public int FooBar {{ get; }}
+        public Task<int> FooBar {{ get; }}
     }}
 
     public class FooTests
@@ -598,23 +631,24 @@ public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressi
         Settings = AnalyzersSettings.CreateWithSuppressions("P:MyNamespace.Foo`1.Bar", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
 namespace MyNamespace
 {{
-    public class Foo<T>
+    public class Foo<T> where T : Task
     {{
         public T Bar {{ get; }}
 
-        public int FooBar {{ get; }}
+        public Task<int> FooBar {{ get; }}
     }}
 
     public class FooTests
     {{
         public void Test()
         {{
-            var substitute = NSubstitute.Substitute.For<Foo<int>>();
+            var substitute = NSubstitute.Substitute.For<Foo<Task<int>>>();
             {method}(substitute.Bar, new Exception());
             {method}([|substitute.FooBar|], new Exception());
         }}
@@ -629,6 +663,7 @@ public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressi
         Settings = AnalyzersSettings.CreateWithSuppressions("M:MyNamespace.Foo.Bar(System.Int32,System.Int32)", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -636,14 +671,14 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public int Bar(int x)
+        public Task<int> Bar(int x)
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
 
-        public int Bar(int x, int y)
+        public Task<int> Bar(int x, int y)
         {{
-            return 2;
+            return Task.FromResult(2);
         }}
     }}
 
@@ -666,6 +701,7 @@ public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressi
         Settings = AnalyzersSettings.CreateWithSuppressions("M:MyNamespace.Foo.Bar``1(``0,``0)", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -673,14 +709,14 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public int Bar(int x)
+        public Task<int> Bar(int x)
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
 
-        public int Bar<T>(T x, T y)
+        public Task<int> Bar<T>(T x, T y)
         {{
-            return 2;
+            return Task.FromResult(2);
         }}
     }}
 
@@ -703,6 +739,7 @@ public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressi
         Settings = AnalyzersSettings.CreateWithSuppressions("P:MyNamespace.Foo.Item(System.Int32,System.Int32)", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -710,8 +747,8 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public int this[int x] => 0;
-        public int this[int x, int y] => 0;
+        public Task<int> this[int x] => Task.FromResult(0);
+        public Task<int> this[int x, int y] => Task.FromResult(0);
     }}
 
     public class FooTests
@@ -733,6 +770,7 @@ public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressi
         Settings = AnalyzersSettings.CreateWithSuppressions("P:MyNamespace.Foo`1.Item(`0,`0)", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -740,8 +778,8 @@ namespace MyNamespace
 {{
     public class Foo<T>
     {{
-        public int this[T x] => 0;
-        public int this[T x, T y] => 0;
+        public Task<int> this[T x] => Task.FromResult(0);
+        public Task<int> this[T x, T y] => Task.FromResult(0);
     }}
 
     public class FooTests
@@ -763,6 +801,7 @@ public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressi
         Settings = AnalyzersSettings.CreateWithSuppressions("T:MyNamespace.Foo", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -770,21 +809,21 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public int Bar {{ get; set; }}
-        public int this[int x] => 0;
-        public int FooBar()
+        public Task<int> Bar {{ get; set; }}
+        public Task<int> this[int x] => Task.FromResult(0);
+        public Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
     }}
 
     public class FooBarBar
     {{
-        public int Bar {{ get;set; }}
-        public int this[int x] => 0;
-        public int FooBar()
+        public Task<int> Bar {{ get;set; }}
+        public Task<int> this[int x] => Task.FromResult(0);
+        public Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
     }}
 
@@ -824,6 +863,7 @@ public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressi
         Settings = AnalyzersSettings.CreateWithSuppressions("T:MyNamespace.Foo`1", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -831,21 +871,21 @@ namespace MyNamespace
 {{
     public class Foo<T>
     {{
-        public int Bar {{ get; set; }}
-        public int this[int x] => 0;
-        public int FooBar()
+        public Task<int> Bar {{ get; set; }}
+        public Task<int> this[int x] => Task.FromResult(0);
+        public Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
     }}
 
     public class FooBarBar<T>
     {{
-        public int Bar {{ get;set; }}
-        public int this[int x] => 0;
-        public int FooBar()
+        public Task<int> Bar {{ get;set; }}
+        public Task<int> this[int x] => Task.FromResult(0);
+        public Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
     }}
 
@@ -885,6 +925,7 @@ public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressi
         Settings = AnalyzersSettings.CreateWithSuppressions("N:MyNamespace", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -892,11 +933,11 @@ namespace MyOtherNamespace
 {{
     public class FooBarBar
     {{
-        public int Bar {{ get; set; }}
-        public int this[int x] => 0;
-        public int FooBar()
+        public Task<int> Bar {{ get; set; }}
+        public Task<int> this[int x] => Task.FromResult(0);
+        public Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
     }}
 }}
@@ -906,11 +947,11 @@ namespace MyNamespace
     using MyOtherNamespace;
     public class Foo
     {{
-        public int Bar {{ get; set; }}
-        public int this[int x] => 0;
-        public int FooBar()
+        public Task<int> Bar {{ get; set; }}
+        public Task<int> this[int x] => Task.FromResult(0);
+        public Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
     }}
 
@@ -947,9 +988,10 @@ public void Test()
 
     public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressingExtensionMethod(string method)
     {
-        Settings = AnalyzersSettings.CreateWithSuppressions("M:MyNamespace.MyExtensions.GetBar(System.Object)~System.Int32", NonVirtualSetupSpecificationDescriptor.Id);
+        Settings = AnalyzersSettings.CreateWithSuppressions("M:MyNamespace.MyExtensions.GetBar(System.Object)~System.Threading.Tasks.Task{System.Int32}", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -970,20 +1012,20 @@ public static class MyExtensions
     {{
         public static IBar Bar {{ get; set; }}
 
-        public static int GetBar(this object @object)
+        public static Task<int> GetBar(this object @object)
         {{
             return Bar.Foo(@object);
         }}
 
-        public static int GetFooBar(this object @object)
+        public static Task<int> GetFooBar(this object @object)
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
     }}
 
     public interface IBar
     {{
-        int Foo(object @obj);
+        Task<int> Foo(object @obj);
     }}
 }}";
 
@@ -993,6 +1035,7 @@ public interface IBar
     public override async Task ReportsDiagnostics_WhenSettingValueForInternalVirtualMember_AndInternalsVisibleToNotApplied(string method, string call, string message)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -1000,16 +1043,16 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        internal virtual object Bar {{ get; }}
+        internal virtual Task<int> Bar {{ get; }}
 
-        internal virtual object FooBar()
+        internal virtual Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
 
-        internal virtual object this[int x]
+        internal virtual Task<int> this[int x]
         {{
-            get {{ return 1; }}
+            get {{ return Task.FromResult(1); }}
         }}
     }}
 
@@ -1031,6 +1074,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForInternalVirtualMember_AndInternalsVisibleToApplied(string method, string call)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 using System.Runtime.CompilerServices;
@@ -1042,16 +1086,16 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        internal virtual object Bar {{ get; }}
+        internal virtual Task<int> Bar {{ get; }}
 
-        internal virtual object FooBar()
+        internal virtual Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
 
-        internal virtual object this[int x]
+        internal virtual Task<int> this[int x]
         {{
-            get {{ return 1; }}
+            get {{ return Task.FromResult(1); }}
         }}
     }}
 
@@ -1073,25 +1117,26 @@ public void Test()
     public override async Task ReportsDiagnostics_WhenSettingValueForInternalVirtualMember_AndInternalsVisibleToAppliedToWrongAssembly(string method, string call, string message)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
-using System.Runtime.CompilerServices;
 using NSubstitute.ExceptionExtensions;
+using System.Runtime.CompilerServices;
 [assembly: InternalsVisibleTo(""OtherAssembly"")]
 
 namespace MyNamespace
 {{
     public class Foo
     {{
-        internal virtual object Bar {{ get; }}
+        internal virtual Task<int> Bar {{ get; }}
 
-        internal virtual object FooBar()
+        internal virtual Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
 
-        internal virtual object this[int x]
+        internal virtual Task<int> this[int x]
         {{
-            get {{ return 1; }}
+            get {{ return Task.FromResult(1); }}
         }}
     }}
 
@@ -1113,6 +1158,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForProtectedInternalVirtualMember(string method, string call)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -1120,16 +1166,16 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        protected internal virtual object Bar {{ get; }}
+        protected internal virtual Task<int> Bar {{ get; }}
 
-        protected internal virtual object FooBar()
+        protected internal virtual Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
 
-        protected internal virtual object this[int x]
+        protected internal virtual Task<int> this[int x]
         {{
-            get {{ return 1; }}
+            get {{ return Task.FromResult(1); }}
         }}
     }}
 
diff --git a/tests/NSubstitute.Analyzers.Tests.CSharp/DiagnosticAnalyzerTests/NonSubstitutableMemberAnalyzerTests/ThrowsAsOrdinaryMethodWithGenericTypeSpecifiedTests.cs b/tests/NSubstitute.Analyzers.Tests.CSharp/DiagnosticAnalyzerTests/NonSubstitutableMemberAnalyzerTests/ThrowsAsOrdinaryMethodWithGenericTypeSpecifiedTests.cs
index de11388e..9e274f86 100644
--- a/tests/NSubstitute.Analyzers.Tests.CSharp/DiagnosticAnalyzerTests/NonSubstitutableMemberAnalyzerTests/ThrowsAsOrdinaryMethodWithGenericTypeSpecifiedTests.cs
+++ b/tests/NSubstitute.Analyzers.Tests.CSharp/DiagnosticAnalyzerTests/NonSubstitutableMemberAnalyzerTests/ThrowsAsOrdinaryMethodWithGenericTypeSpecifiedTests.cs
@@ -1,4 +1,4 @@
-using System.Linq;
+using System.Linq;
 using System.Threading.Tasks;
 using NSubstitute.Analyzers.Shared.Settings;
 using NSubstitute.Analyzers.Tests.Shared.Extensibility;
@@ -6,12 +6,17 @@
 
 namespace NSubstitute.Analyzers.Tests.CSharp.DiagnosticAnalyzerTests.NonSubstitutableMemberAnalyzerTests;
 
-[CombinatoryData("ExceptionExtensions.Throws<Exception>", "ExceptionExtensions.ThrowsForAnyArgs<Exception>")]
+[CombinatoryData(
+    "ExceptionExtensions.Throws<Exception>",
+    "ExceptionExtensions.ThrowsAsync<Exception>",
+    "ExceptionExtensions.ThrowsForAnyArgs<Exception>",
+    "ExceptionExtensions.ThrowsAsyncForAnyArgs<Exception>")]
 public class ThrowsAsOrdinaryMethodWithGenericTypeSpecifiedTests : NonSubstitutableMemberDiagnosticVerifier
 {
     public override async Task ReportsDiagnostics_WhenSettingValueForNonVirtualMethod(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -19,9 +24,9 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public int Bar()
+        public Task<int> Bar()
         {{
-            return 2;
+            return Task.FromResult(1);
         }}
     }}
 
@@ -61,6 +66,7 @@ public void Test()
     public override async Task ReportsDiagnostics_WhenSettingValueForStaticMethod(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -68,9 +74,9 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public static int Bar()
+        public static Task<int> Bar()
         {{
-            return 2;
+            return Task.FromResult(2);
         }}
     }}
 
@@ -89,6 +95,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForVirtualMethod(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -96,9 +103,9 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public virtual int Bar()
+        public virtual Task<int> Bar()
         {{
-            return 2;
+            return Task.FromResult(2);
         }}
     }}
 
@@ -117,6 +124,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForNonSealedOverrideMethod(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -124,15 +132,15 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public virtual int Bar()
+        public virtual Task<int> Bar()
         {{
-            return 2;
+            return Task.FromResult(2);
         }}
     }}
 
     public class Foo2 : Foo
     {{
-        public override int Bar() => 1;
+        public override Task<int> Bar() => Task.FromResult(1);
     }}
 
     public class FooTests
@@ -150,6 +158,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenDataFlowAnalysisIsRequired(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -157,9 +166,9 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public virtual int Bar()
+        public virtual Task<int> Bar()
         {{
-            return 2;
+            return Task.FromResult(2);
         }}
     }}
 
@@ -179,6 +188,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForDelegate(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 using System;
@@ -189,7 +199,7 @@ public class FooTests
     {{
         public void Test()
         {{
-            var substitute = Substitute.For<Func<int>>();
+            var substitute = Substitute.For<Func<Task<int>>>();
             {method}(substitute());
         }}
     }}
@@ -200,6 +210,7 @@ public void Test()
     public override async Task ReportsDiagnostics_WhenSettingValueForSealedOverrideMethod(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -207,15 +218,15 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public virtual int Bar()
+        public virtual Task<int> Bar()
         {{
-            return 2;
+            return Task.FromResult(2);
         }}
     }}
 
     public class Foo2 : Foo
     {{
-        public sealed override int Bar() => 1;
+        public sealed override Task<int> Bar() => Task.FromResult(1);
     }}
 
     public class FooTests
@@ -234,6 +245,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForAbstractMethod(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -241,7 +253,7 @@ namespace MyNamespace
 {{
     public abstract class Foo
     {{
-        public abstract int Bar();
+        public abstract Task<int> Bar();
     }}
 
     public class FooTests
@@ -260,6 +272,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForInterfaceMethod(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -267,7 +280,7 @@ namespace MyNamespace
 {{
     public interface IFoo
     {{
-        int Bar();
+        Task<int> Bar();
     }}
 
     public class FooTests
@@ -285,6 +298,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForInterfaceProperty(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -292,7 +306,7 @@ namespace MyNamespace
 {{
     public interface IFoo
     {{
-        int Bar {{ get; }}
+        Task<int> Bar {{ get; }}
     }}
 
     public class FooTests
@@ -310,6 +324,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForGenericInterfaceMethod(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -317,7 +332,7 @@ namespace MyNamespace
 {{
     public interface IFoo<T>
     {{
-        int Bar<T>();
+        Task<int> Bar<T>();
     }}
 
     public class FooTests
@@ -335,6 +350,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForAbstractProperty(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -342,7 +358,7 @@ namespace MyNamespace
 {{
     public abstract class Foo
     {{
-        public abstract int Bar {{ get; }}
+        public abstract Task<int> Bar {{ get; }}
     }}
 
     public class FooTests
@@ -361,6 +377,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForInterfaceIndexer(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -368,7 +385,7 @@ namespace MyNamespace
 {{
     public interface IFoo
     {{
-        int this[int i] {{ get; }}
+        Task<int> this[int i] {{ get; }}
     }}
 
     public class FooTests
@@ -386,6 +403,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForVirtualProperty(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -393,7 +411,7 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public virtual int Bar {{ get; }}
+        public virtual Task<int> Bar {{ get; }}
     }}
 
     public class FooTests
@@ -412,6 +430,7 @@ public void Test()
     public override async Task ReportsDiagnostics_WhenSettingValueForNonVirtualProperty(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -419,7 +438,7 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public int Bar {{ get; }}
+        public Task<int> Bar {{ get; }}
     }}
 
     public class FooTests
@@ -438,6 +457,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForVirtualIndexer(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -445,7 +465,7 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public virtual int this[int x] => 0;
+        public virtual Task<int> this[int x] => Task.FromResult(0);
     }}
 
     public class FooTests
@@ -463,6 +483,7 @@ public void Test()
     public override async Task ReportsDiagnostics_WhenSettingValueForNonVirtualIndexer(string method)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -470,7 +491,7 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public int this[int x] => 0;
+        public Task<int> this[int x] => Task.FromResult(0);
     }}
 
     public class FooTests
@@ -490,13 +511,14 @@ public override async Task ReportsNoDiagnostics_WhenUsingUnfortunatelyNamedMetho
     {
         var source = $@"
 using System;
+using System.Threading.Tasks;
 namespace NSubstitute
 {{
     public class Foo
     {{
-        public int Bar()
+        public Task<int> Bar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
     }}
 
@@ -507,10 +529,20 @@ public static T Throws<T>(this object value) where T: Exception
             return default(T);
         }}
 
+        public static T ThrowsAsync<T>(this Task value) where T: Exception
+        {{
+            return default(T);
+        }}
+
         public static T ThrowsForAnyArgs<T>(this object value) where T: Exception
         {{
             return default(T);
         }}
+
+        public static T ThrowsAsyncForAnyArgs<T>(this Task value) where T: Exception
+        {{
+            return default(T);
+        }}
     }}
 
     public class FooTests
@@ -530,6 +562,7 @@ public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressi
         Settings = AnalyzersSettings.CreateWithSuppressions("P:MyNamespace.Foo.Bar", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -537,9 +570,9 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public int Bar {{ get; }}
+        public Task<int> Bar {{ get; }}
 
-        public int FooBar {{ get; }}
+        public Task<int> FooBar {{ get; }}
     }}
 
     public class FooTests
@@ -561,23 +594,24 @@ public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressi
         Settings = AnalyzersSettings.CreateWithSuppressions("P:MyNamespace.Foo`1.Bar", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
 namespace MyNamespace
 {{
-    public class Foo<T>
+    public class Foo<T> where T : Task
     {{
         public T Bar {{ get; }}
 
-        public int FooBar {{ get; }}
+        public Task<int> FooBar {{ get; }}
     }}
 
     public class FooTests
     {{
         public void Test()
         {{
-            var substitute = NSubstitute.Substitute.For<Foo<int>>();
+            var substitute = NSubstitute.Substitute.For<Foo<Task<int>>>();
             {method}(substitute.Bar);
             {method}([|substitute.FooBar|]);
         }}
@@ -592,6 +626,7 @@ public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressi
         Settings = AnalyzersSettings.CreateWithSuppressions("M:MyNamespace.Foo.Bar(System.Int32,System.Int32)", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -599,14 +634,14 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public int Bar(int x)
+        public Task<int> Bar(int x)
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
 
-        public int Bar(int x, int y)
+        public Task<int> Bar(int x, int y)
         {{
-            return 2;
+            return Task.FromResult(2);
         }}
     }}
 
@@ -629,6 +664,7 @@ public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressi
         Settings = AnalyzersSettings.CreateWithSuppressions("M:MyNamespace.Foo.Bar``1(``0,``0)", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -636,14 +672,14 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public int Bar(int x)
+        public Task<int> Bar(int x)
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
 
-        public int Bar<T>(T x, T y)
+        public Task<int> Bar<T>(T x, T y)
         {{
-            return 2;
+            return Task.FromResult(2);
         }}
     }}
 
@@ -666,6 +702,7 @@ public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressi
         Settings = AnalyzersSettings.CreateWithSuppressions("P:MyNamespace.Foo.Item(System.Int32,System.Int32)", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -673,8 +710,8 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public int this[int x] => 0;
-        public int this[int x, int y] => 0;
+        public Task<int> this[int x] => Task.FromResult(0);
+        public Task<int> this[int x, int y] => Task.FromResult(0);
     }}
 
     public class FooTests
@@ -696,6 +733,7 @@ public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressi
         Settings = AnalyzersSettings.CreateWithSuppressions("P:MyNamespace.Foo`1.Item(`0,`0)", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -703,8 +741,8 @@ namespace MyNamespace
 {{
     public class Foo<T>
     {{
-        public int this[T x] => 0;
-        public int this[T x, T y] => 0;
+        public Task<int> this[T x] => Task.FromResult(0);
+        public Task<int> this[T x, T y] => Task.FromResult(0);
     }}
 
     public class FooTests
@@ -726,6 +764,7 @@ public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressi
         Settings = AnalyzersSettings.CreateWithSuppressions("T:MyNamespace.Foo", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -733,21 +772,21 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        public int Bar {{ get; set; }}
-        public int this[int x] => 0;
-        public int FooBar()
+        public Task<int> Bar {{ get; set; }}
+        public Task<int> this[int x] => Task.FromResult(0);
+        public Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
     }}
 
     public class FooBarBar
     {{
-        public int Bar {{ get;set; }}
-        public int this[int x] => 0;
-        public int FooBar()
+        public Task<int> Bar {{ get;set; }}
+        public Task<int> this[int x] => Task.FromResult(0);
+        public Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
     }}
 
@@ -787,6 +826,7 @@ public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressi
         Settings = AnalyzersSettings.CreateWithSuppressions("T:MyNamespace.Foo`1", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -794,21 +834,21 @@ namespace MyNamespace
 {{
     public class Foo<T>
     {{
-        public int Bar {{ get; set; }}
-        public int this[int x] => 0;
-        public int FooBar()
+        public Task<int> Bar {{ get; set; }}
+        public Task<int> this[int x] => Task.FromResult(0);
+        public Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
     }}
 
     public class FooBarBar<T>
     {{
-        public int Bar {{ get;set; }}
-        public int this[int x] => 0;
-        public int FooBar()
+        public Task<int> Bar {{ get;set; }}
+        public Task<int> this[int x] => Task.FromResult(0);
+        public Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
     }}
 
@@ -848,6 +888,7 @@ public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressi
         Settings = AnalyzersSettings.CreateWithSuppressions("N:MyNamespace", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -855,11 +896,11 @@ namespace MyOtherNamespace
 {{
     public class FooBarBar
     {{
-        public int Bar {{ get; set; }}
-        public int this[int x] => 0;
-        public int FooBar()
+        public Task<int> Bar {{ get; set; }}
+        public Task<int> this[int x] => Task.FromResult(0);
+        public Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
     }}
 }}
@@ -869,11 +910,11 @@ namespace MyNamespace
     using MyOtherNamespace;
     public class Foo
     {{
-        public int Bar {{ get; set; }}
-        public int this[int x] => 0;
-        public int FooBar()
+        public Task<int> Bar {{ get; set; }}
+        public Task<int> this[int x] => Task.FromResult(0);
+        public Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
     }}
 
@@ -910,9 +951,10 @@ public void Test()
 
     public override async Task ReportsNoDiagnosticsForSuppressedMember_WhenSuppressingExtensionMethod(string method)
     {
-        Settings = AnalyzersSettings.CreateWithSuppressions("M:MyNamespace.MyExtensions.GetBar(System.Object)~System.Int32", NonVirtualSetupSpecificationDescriptor.Id);
+        Settings = AnalyzersSettings.CreateWithSuppressions("M:MyNamespace.MyExtensions.GetBar(System.Object)~System.Threading.Tasks.Task{System.Int32}", NonVirtualSetupSpecificationDescriptor.Id);
 
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -933,20 +975,20 @@ public static class MyExtensions
     {{
         public static IBar Bar {{ get; set; }}
 
-        public static int GetBar(this object @object)
+        public static Task<int> GetBar(this object @object)
         {{
             return Bar.Foo(@object);
         }}
 
-        public static int GetFooBar(this object @object)
+        public static Task<int> GetFooBar(this object @object)
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
     }}
 
     public interface IBar
     {{
-        int Foo(object @obj);
+        Task<int> Foo(object @obj);
     }}
 }}";
 
@@ -956,6 +998,7 @@ public interface IBar
     public override async Task ReportsDiagnostics_WhenSettingValueForInternalVirtualMember_AndInternalsVisibleToNotApplied(string method, string call, string message)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -963,16 +1006,16 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        internal virtual object Bar {{ get; }}
+        internal virtual Task<int> Bar {{ get; }}
 
-        internal virtual object FooBar()
+        internal virtual Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
 
-        internal virtual object this[int x]
+        internal virtual Task<int> this[int x]
         {{
-            get {{ return 1; }}
+            get {{ return Task.FromResult(1); }}
         }}
     }}
 
@@ -992,6 +1035,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForInternalVirtualMember_AndInternalsVisibleToApplied(string method, string call)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 using System.Runtime.CompilerServices;
@@ -1003,16 +1047,16 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        internal virtual object Bar {{ get; }}
+        internal virtual Task<int> Bar {{ get; }}
 
-        internal virtual object FooBar()
+        internal virtual Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
 
-        internal virtual object this[int x]
+        internal virtual Task<int> this[int x]
         {{
-            get {{ return 1; }}
+            get {{ return Task.FromResult(1); }}
         }}
     }}
 
@@ -1032,25 +1076,26 @@ public void Test()
     public override async Task ReportsDiagnostics_WhenSettingValueForInternalVirtualMember_AndInternalsVisibleToAppliedToWrongAssembly(string method, string call, string message)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
-using System.Runtime.CompilerServices;
 using NSubstitute.ExceptionExtensions;
+using System.Runtime.CompilerServices;
 [assembly: InternalsVisibleTo(""OtherAssembly"")]
 
 namespace MyNamespace
 {{
     public class Foo
     {{
-        internal virtual object Bar {{ get; }}
+        internal virtual Task<int> Bar {{ get; }}
 
-        internal virtual object FooBar()
+        internal virtual Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
 
-        internal virtual object this[int x]
+        internal virtual Task<int> this[int x]
         {{
-            get {{ return 1; }}
+            get {{ return Task.FromResult(1); }}
         }}
     }}
 
@@ -1070,6 +1115,7 @@ public void Test()
     public override async Task ReportsNoDiagnostics_WhenSettingValueForProtectedInternalVirtualMember(string method, string call)
     {
         var source = $@"using System;
+using System.Threading.Tasks;
 using NSubstitute;
 using NSubstitute.ExceptionExtensions;
 
@@ -1077,16 +1123,16 @@ namespace MyNamespace
 {{
     public class Foo
     {{
-        protected internal virtual object Bar {{ get; }}
+        protected internal virtual Task<int> Bar {{ get; }}
 
-        protected internal virtual object FooBar()
+        protected internal virtual Task<int> FooBar()
         {{
-            return 1;
+            return Task.FromResult(1);
         }}
 
-        protected internal virtual object this[int x]
+        protected internal virtual Task<int> this[int x]
         {{
-            get {{ return 1; }}
+            get {{ return Task.FromResult(1); }}
         }}
     }}