diff --git a/YamlDotNet.Samples/ConvertYamlToJson.cs b/YamlDotNet.Samples/ConvertYamlToJson.cs
index 9ad59e5bb..4639a4bc6 100644
--- a/YamlDotNet.Samples/ConvertYamlToJson.cs
+++ b/YamlDotNet.Samples/ConvertYamlToJson.cs
@@ -20,7 +20,6 @@
 // SOFTWARE.
 
 using System.IO;
-using Xunit.Abstractions;
 using YamlDotNet.Samples.Helpers;
 using YamlDotNet.Serialization;
 
diff --git a/YamlDotNet.Samples/DeserializeObjectGraph.cs b/YamlDotNet.Samples/DeserializeObjectGraph.cs
index 24303aa4c..9833bc314 100644
--- a/YamlDotNet.Samples/DeserializeObjectGraph.cs
+++ b/YamlDotNet.Samples/DeserializeObjectGraph.cs
@@ -22,7 +22,7 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
-using Xunit.Abstractions;
+
 using YamlDotNet.Samples.Helpers;
 using YamlDotNet.Serialization;
 using YamlDotNet.Serialization.NamingConventions;
diff --git a/YamlDotNet.Samples/DeserializingMultipleDocuments.cs b/YamlDotNet.Samples/DeserializingMultipleDocuments.cs
index 8350fe933..73009ad38 100644
--- a/YamlDotNet.Samples/DeserializingMultipleDocuments.cs
+++ b/YamlDotNet.Samples/DeserializingMultipleDocuments.cs
@@ -21,7 +21,6 @@
 
 using System.Collections.Generic;
 using System.IO;
-using Xunit.Abstractions;
 using YamlDotNet.Core;
 using YamlDotNet.Core.Events;
 using YamlDotNet.Samples.Helpers;
diff --git a/YamlDotNet.Samples/LoadingAYamlStream.cs b/YamlDotNet.Samples/LoadingAYamlStream.cs
index d5d210892..4c3bff249 100644
--- a/YamlDotNet.Samples/LoadingAYamlStream.cs
+++ b/YamlDotNet.Samples/LoadingAYamlStream.cs
@@ -20,7 +20,6 @@
 // SOFTWARE.
 
 using System.IO;
-using Xunit.Abstractions;
 using YamlDotNet.RepresentationModel;
 using YamlDotNet.Samples.Helpers;
 
diff --git a/YamlDotNet.Samples/SerializeObjectGraph.cs b/YamlDotNet.Samples/SerializeObjectGraph.cs
index b73b57446..8fa23f6b1 100644
--- a/YamlDotNet.Samples/SerializeObjectGraph.cs
+++ b/YamlDotNet.Samples/SerializeObjectGraph.cs
@@ -20,7 +20,6 @@
 // SOFTWARE.
 
 using System;
-using Xunit.Abstractions;
 using YamlDotNet.Samples.Helpers;
 using YamlDotNet.Serialization;
 
@@ -92,33 +91,33 @@ public void Main()
     public class Address
     {
         public string street { get; set; }
-        public string city { get; set; }
-        public string state { get; set; }
+        public string city   { get; set; }
+        public string state  { get; set; }
     }
 
     public class Receipt
     {
-        public string receipt { get; set; }
-        public DateTime date { get; set; }
-        public Customer customer { get; set; }
-        public Item[] items { get; set; }
-        public Address bill_to { get; set; }
-        public Address ship_to { get; set; }
-        public string specialDelivery { get; set; }
+        public string   receipt         { get; set; }
+        public DateTime date            { get; set; }
+        public Customer customer        { get; set; }
+        public Item[]   items           { get; set; }
+        public Address  bill_to         { get; set; }
+        public Address  ship_to         { get; set; }
+        public string   specialDelivery { get; set; }
     }
 
     public class Customer
     {
-        public string given { get; set; }
+        public string given  { get; set; }
         public string family { get; set; }
     }
 
     public class Item
     {
-        public string part_no { get; set; }
-        public string descrip { get; set; }
-        public decimal price { get; set; }
-        public int quantity { get; set; }
+        public string  part_no  { get; set; }
+        public string  descrip  { get; set; }
+        public decimal price    { get; set; }
+        public int     quantity { get; set; }
     }
 #pragma warning restore IDE1006 // Naming Styles
 }
diff --git a/YamlDotNet/Core/ParserExtensions.cs b/YamlDotNet/Core/ParserExtensions.cs
index 40abc231e..d325d987f 100644
--- a/YamlDotNet/Core/ParserExtensions.cs
+++ b/YamlDotNet/Core/ParserExtensions.cs
@@ -51,7 +51,7 @@ public static T Consume<T>(this IParser parser) where T : ParsingEvent
         /// </summary>
         /// <typeparam name="T">Type of the <see cref="ParsingEvent"/>.</typeparam>
         /// <returns>Returns true if the current event is of type T; otherwise returns null.</returns>
-        public static bool TryConsume<T>(this IParser parser, [MaybeNullWhen(false)] out T @event) where T : ParsingEvent
+        public static bool TryConsume<T>(this IParser parser, out T @event) where T : ParsingEvent
         {
             if (parser.Accept(out @event!))
             {
@@ -86,7 +86,7 @@ public static T Require<T>(this IParser parser) where T : ParsingEvent
         /// </summary>
         /// <typeparam name="T">Type of the event.</typeparam>
         /// <returns>Returns true if the current event is of type <typeparamref name="T"/>. Otherwise returns false.</returns>
-        public static bool Accept<T>(this IParser parser, [MaybeNullWhen(false)] out T @event) where T : ParsingEvent
+        public static bool Accept<T>(this IParser parser, out T @event) where T : ParsingEvent
         {
             if (parser.Current == null)
             {
@@ -129,13 +129,13 @@ public static T Expect<T>(this IParser parser) where T : ParsingEvent
         }
 
         [Obsolete("Please use TryConsume<T>(out var evt) instead")]
-        public static T? Allow<T>(this IParser parser) where T : ParsingEvent
+        public static T Allow<T>(this IParser parser) where T : ParsingEvent
         {
             return parser.TryConsume<T>(out var @event) ? @event : default;
         }
 
         [Obsolete("Please use Accept<T>(out var evt) instead")]
-        public static T? Peek<T>(this IParser parser) where T : ParsingEvent
+        public static T Peek<T>(this IParser parser) where T : ParsingEvent
         {
             return parser.Accept<T>(out var @event) ? @event : default;
         }
diff --git a/YamlDotNet/Helpers/ExpressionExtensions.cs b/YamlDotNet/Helpers/ExpressionExtensions.cs
index 19487bd23..9ef1fbfe5 100644
--- a/YamlDotNet/Helpers/ExpressionExtensions.cs
+++ b/YamlDotNet/Helpers/ExpressionExtensions.cs
@@ -47,7 +47,7 @@ public static PropertyInfo AsProperty(this LambdaExpression propertyAccessor)
             return property;
         }
 
-        private static TMemberInfo? TryGetMemberExpression<TMemberInfo>(LambdaExpression lambdaExpression)
+        private static TMemberInfo TryGetMemberExpression<TMemberInfo>(LambdaExpression lambdaExpression)
             where TMemberInfo : MemberInfo
         {
             if (lambdaExpression.Parameters.Count != 1)
diff --git a/YamlDotNet/Helpers/OrderedDictionary.cs b/YamlDotNet/Helpers/OrderedDictionary.cs
index cf602fbbb..bda747f3f 100644
--- a/YamlDotNet/Helpers/OrderedDictionary.cs
+++ b/YamlDotNet/Helpers/OrderedDictionary.cs
@@ -140,7 +140,7 @@ public void RemoveAt(int index)
 #pragma warning disable 8767 // Nullability of reference types in type of parameter ... doesn't match implicitly implemented member
 #endif
 
-        public bool TryGetValue(TKey key, [MaybeNullWhen(false)] out TValue value) =>
+        public bool TryGetValue(TKey key, out TValue value) =>
             dictionary.TryGetValue(key, out value);
 
 #if !(NETCOREAPP3_1)
diff --git a/YamlDotNet/RepresentationModel/DocumentLoadingState.cs b/YamlDotNet/RepresentationModel/DocumentLoadingState.cs
index e424c39be..3d41b80e0 100644
--- a/YamlDotNet/RepresentationModel/DocumentLoadingState.cs
+++ b/YamlDotNet/RepresentationModel/DocumentLoadingState.cs
@@ -81,7 +81,7 @@ public YamlNode GetNode(AnchorName anchor, Mark start, Mark end)
         /// <param name="anchor">The anchor.</param>
         /// <param name="node">The node that was retrieved.</param>
         /// <returns>true if the anchor was found; otherwise false.</returns>
-        public bool TryGetNode(AnchorName anchor, [NotNullWhen(true)] out YamlNode? node)
+        public bool TryGetNode(AnchorName anchor, out YamlNode? node)
         {
             return anchors.TryGetValue(anchor, out node);
         }
diff --git a/YamlDotNet/RepresentationModel/YamlNodeIdentityEqualityComparer.cs b/YamlDotNet/RepresentationModel/YamlNodeIdentityEqualityComparer.cs
index 383fe85f5..3a589e1d2 100644
--- a/YamlDotNet/RepresentationModel/YamlNodeIdentityEqualityComparer.cs
+++ b/YamlDotNet/RepresentationModel/YamlNodeIdentityEqualityComparer.cs
@@ -32,7 +32,7 @@ public sealed class YamlNodeIdentityEqualityComparer : IEqualityComparer<YamlNod
         #region IEqualityComparer<YamlNode> Members
 
         /// <summary />
-        public bool Equals([AllowNull] YamlNode x, [AllowNull] YamlNode y)
+        public bool Equals(YamlNode x, YamlNode y)
         {
             return ReferenceEquals(x, y);
         }
diff --git a/YamlDotNet/Serialization/ITypeInspector.cs b/YamlDotNet/Serialization/ITypeInspector.cs
index ba914b3c0..a2be74df6 100644
--- a/YamlDotNet/Serialization/ITypeInspector.cs
+++ b/YamlDotNet/Serialization/ITypeInspector.cs
@@ -49,6 +49,6 @@ public interface ITypeInspector
         /// found in <paramref name="type"/>
         /// </param>
         /// <returns></returns>
-        IPropertyDescriptor GetProperty(Type type, object? container, string name, [MaybeNullWhen(true)] bool ignoreUnmatched);
+        IPropertyDescriptor GetProperty(Type type, object? container, string name, bool ignoreUnmatched);
     }
 }
diff --git a/YamlDotNet/Serialization/TypeInspectors/TypeInspectorSkeleton.cs b/YamlDotNet/Serialization/TypeInspectors/TypeInspectorSkeleton.cs
index d062d2cce..c0b69be8a 100644
--- a/YamlDotNet/Serialization/TypeInspectors/TypeInspectorSkeleton.cs
+++ b/YamlDotNet/Serialization/TypeInspectors/TypeInspectorSkeleton.cs
@@ -31,7 +31,7 @@ public abstract class TypeInspectorSkeleton : ITypeInspector
     {
         public abstract IEnumerable<IPropertyDescriptor> GetProperties(Type type, object? container);
 
-        public IPropertyDescriptor GetProperty(Type type, object? container, string name, [MaybeNullWhen(true)] bool ignoreUnmatched)
+        public IPropertyDescriptor GetProperty(Type type, object? container, string name, bool ignoreUnmatched)
         {
             var candidates = GetProperties(type, container)
                 .Where(p => p.Name == name);
diff --git a/YamlDotNet/Serialization/Utilities/ObjectAnchorCollection.cs b/YamlDotNet/Serialization/Utilities/ObjectAnchorCollection.cs
index 708acbb40..f326ca837 100644
--- a/YamlDotNet/Serialization/Utilities/ObjectAnchorCollection.cs
+++ b/YamlDotNet/Serialization/Utilities/ObjectAnchorCollection.cs
@@ -50,7 +50,7 @@ public void Add(string anchor, object @object)
         /// <param name="object">The object.</param>
         /// <param name="anchor">The anchor.</param>
         /// <returns></returns>
-        public bool TryGetAnchor(object @object, [MaybeNullWhen(false)] out string? anchor)
+        public bool TryGetAnchor(object @object, out string? anchor)
         {
             return anchorsByObject.TryGetValue(@object, out anchor);
         }
diff --git a/YamlDotNet/Serialization/YamlAttributeOverrides.cs b/YamlDotNet/Serialization/YamlAttributeOverrides.cs
index 14ed231da..11bc75f93 100644
--- a/YamlDotNet/Serialization/YamlAttributeOverrides.cs
+++ b/YamlDotNet/Serialization/YamlAttributeOverrides.cs
@@ -107,7 +107,7 @@ public int Matches(Type matchType)
 
         private readonly Dictionary<AttributeKey, List<AttributeMapping>> overrides = new Dictionary<AttributeKey, List<AttributeMapping>>();
 
-        public T? GetAttribute<T>(Type type, string member) where T : Attribute
+        public T GetAttribute<T>(Type type, string member) where T : Attribute
         {
             if (overrides.TryGetValue(new AttributeKey(typeof(T), member), out var mappings))
             {