diff --git a/samples/SimpleClient/SimpleClient.csproj b/samples/SimpleClient/SimpleClient.csproj
index 0f3d571..6bab768 100644
--- a/samples/SimpleClient/SimpleClient.csproj
+++ b/samples/SimpleClient/SimpleClient.csproj
@@ -3,6 +3,7 @@
   <PropertyGroup>
     <OutputType>Exe</OutputType>
     <TargetFramework>netcoreapp2.0</TargetFramework>
+    <LangVersion>latest</LangVersion>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/samples/SimpleServer/SimpleServer.csproj b/samples/SimpleServer/SimpleServer.csproj
index 1215cce..6a15311 100644
--- a/samples/SimpleServer/SimpleServer.csproj
+++ b/samples/SimpleServer/SimpleServer.csproj
@@ -3,6 +3,7 @@
   <PropertyGroup>
     <OutputType>Exe</OutputType>
     <TargetFramework>netcoreapp2.0</TargetFramework>
+    <LangVersion>latest</LangVersion>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/src/CoAPNet.Server/CoAPNet.Server.csproj b/src/CoAPNet.Server/CoAPNet.Server.csproj
index 4aff0b5..2cbc73a 100644
--- a/src/CoAPNet.Server/CoAPNet.Server.csproj
+++ b/src/CoAPNet.Server/CoAPNet.Server.csproj
@@ -4,6 +4,7 @@
     <TargetFrameworks>netstandard1.3;netstandard2.0;netcoreapp2.0</TargetFrameworks>
     <DebugType Condition="$(Configuration)=='AppVeyor'">full</DebugType>
     <GeneratePackageOnBuild>True</GeneratePackageOnBuild>
+    <LangVersion>latest</LangVersion>
     <PackageId>NZSmartie.CoAPNet.Server</PackageId>
     <Version>0.3.8</Version>
     <PackageVersion>0.3.8</PackageVersion>
diff --git a/src/CoAPNet.Udp/CoAPNet.Udp.csproj b/src/CoAPNet.Udp/CoAPNet.Udp.csproj
index 47a4467..db9e771 100644
--- a/src/CoAPNet.Udp/CoAPNet.Udp.csproj
+++ b/src/CoAPNet.Udp/CoAPNet.Udp.csproj
@@ -3,6 +3,7 @@
   <PropertyGroup>
     <TargetFrameworks>netstandard1.3;netstandard2.0;netcoreapp2.0</TargetFrameworks>
     <PackageId>NZSmartie.CoAPNet.Udp</PackageId>
+    <LangVersion>latest</LangVersion>
     <Version>0.3.8</Version>
     <PackageVersion>0.3.8</PackageVersion>
     <Authors>Roman Vaughan</Authors>
diff --git a/src/CoAPNet/CoAPNet.csproj b/src/CoAPNet/CoAPNet.csproj
index 84e37aa..85fd7b1 100644
--- a/src/CoAPNet/CoAPNet.csproj
+++ b/src/CoAPNet/CoAPNet.csproj
@@ -3,6 +3,7 @@
     <TargetFrameworks>netstandard1.3</TargetFrameworks>
     <DebugType Condition="$(Configuration)=='AppVeyor'">full</DebugType>
     <GeneratePackageOnBuild>True</GeneratePackageOnBuild>
+    <LangVersion>latest</LangVersion>
     <PackageId>NZSmartie.CoAPNet</PackageId>
     <Version>0.3.8.0</Version>
     <PackageVersion>0.3.8</PackageVersion>
diff --git a/tests/CoAPNet.Tests/CoAPNet.Tests.csproj b/tests/CoAPNet.Tests/CoAPNet.Tests.csproj
index f5aeab5..4589069 100644
--- a/tests/CoAPNet.Tests/CoAPNet.Tests.csproj
+++ b/tests/CoAPNet.Tests/CoAPNet.Tests.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <TargetFramework>netcoreapp2.0</TargetFramework>
+    <LangVersion>latest</LangVersion>
     <DebugType Condition="$(Configuration)=='AppVeyor'">full</DebugType>
     <Configurations>Debug;Release;AppVeyor</Configurations>
   </PropertyGroup>
diff --git a/tests/CoApNet.Udp.Tests/CoApNet.Udp.Tests.csproj b/tests/CoApNet.Udp.Tests/CoApNet.Udp.Tests.csproj
index 27442f1..2bfaf48 100644
--- a/tests/CoApNet.Udp.Tests/CoApNet.Udp.Tests.csproj
+++ b/tests/CoApNet.Udp.Tests/CoApNet.Udp.Tests.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <TargetFramework>netcoreapp2.0</TargetFramework>
+    <LangVersion>latest</LangVersion>
     <DebugType Condition="$(Configuration)=='AppVeyor'">full</DebugType>
     <Configurations>Debug;Release;AppVeyor</Configurations>
   </PropertyGroup>