diff --git a/projects/RabbitMQ.Client.OpenTelemetry/RabbitMQ.Client.OpenTelemetry.csproj b/projects/RabbitMQ.Client.OpenTelemetry/RabbitMQ.Client.OpenTelemetry.csproj
index 1b334ef77..10efe3c88 100644
--- a/projects/RabbitMQ.Client.OpenTelemetry/RabbitMQ.Client.OpenTelemetry.csproj
+++ b/projects/RabbitMQ.Client.OpenTelemetry/RabbitMQ.Client.OpenTelemetry.csproj
@@ -27,7 +27,7 @@
     <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
     <PackageOutputPath>../../packages</PackageOutputPath>
     <PackageReadmeFile>README.md</PackageReadmeFile>
-    <LangVersion>9.0</LangVersion>
+    <LangVersion>12.0</LangVersion>
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(Configuration)' == 'Release' And '$(CI)' == 'true'">
diff --git a/projects/Test/Applications/CreateChannel/CreateChannel.csproj b/projects/Test/Applications/CreateChannel/CreateChannel.csproj
index 82fe5c3fe..ba23a90df 100644
--- a/projects/Test/Applications/CreateChannel/CreateChannel.csproj
+++ b/projects/Test/Applications/CreateChannel/CreateChannel.csproj
@@ -14,7 +14,7 @@
   
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <LangVersion>9.0</LangVersion>
+    <LangVersion>12.0</LangVersion>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/projects/Test/Applications/MassPublish/MassPublish.csproj b/projects/Test/Applications/MassPublish/MassPublish.csproj
index 82fe5c3fe..ba23a90df 100644
--- a/projects/Test/Applications/MassPublish/MassPublish.csproj
+++ b/projects/Test/Applications/MassPublish/MassPublish.csproj
@@ -14,7 +14,7 @@
   
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <LangVersion>9.0</LangVersion>
+    <LangVersion>12.0</LangVersion>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/projects/Test/Applications/PublisherConfirms/PublisherConfirms.csproj b/projects/Test/Applications/PublisherConfirms/PublisherConfirms.csproj
index 35cb61e00..0b0de7dd0 100644
--- a/projects/Test/Applications/PublisherConfirms/PublisherConfirms.csproj
+++ b/projects/Test/Applications/PublisherConfirms/PublisherConfirms.csproj
@@ -9,7 +9,7 @@
   <PropertyGroup>
     <OutputType>Exe</OutputType>
     <Nullable>enable</Nullable>
-    <LangVersion>9.0</LangVersion>
+    <LangVersion>12.0</LangVersion>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/projects/Test/Common/Common.csproj b/projects/Test/Common/Common.csproj
index 1bbd691b7..cc5869cee 100644
--- a/projects/Test/Common/Common.csproj
+++ b/projects/Test/Common/Common.csproj
@@ -16,7 +16,7 @@
     <AssemblyOriginatorKeyFile>../../rabbit.snk</AssemblyOriginatorKeyFile>
     <SignAssembly>true</SignAssembly>
     <IsTestProject>false</IsTestProject>
-    <LangVersion>9.0</LangVersion>
+    <LangVersion>12.0</LangVersion>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/projects/Test/Integration/Integration.csproj b/projects/Test/Integration/Integration.csproj
index 483b52932..585302a85 100644
--- a/projects/Test/Integration/Integration.csproj
+++ b/projects/Test/Integration/Integration.csproj
@@ -16,7 +16,7 @@
     <AssemblyOriginatorKeyFile>../../rabbit.snk</AssemblyOriginatorKeyFile>
     <SignAssembly>true</SignAssembly>
     <IsTestProject>true</IsTestProject>
-    <LangVersion>9.0</LangVersion>
+    <LangVersion>12.0</LangVersion>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/projects/Test/OAuth2/OAuth2.csproj b/projects/Test/OAuth2/OAuth2.csproj
index 8dd9b28f5..6710e5d21 100644
--- a/projects/Test/OAuth2/OAuth2.csproj
+++ b/projects/Test/OAuth2/OAuth2.csproj
@@ -16,7 +16,7 @@
     <AssemblyOriginatorKeyFile>../../rabbit.snk</AssemblyOriginatorKeyFile>
     <SignAssembly>true</SignAssembly>
     <IsTestProject>true</IsTestProject>
-    <LangVersion>9.0</LangVersion>
+    <LangVersion>12.0</LangVersion>
     <Nullable>enable</Nullable>
   </PropertyGroup>
 
diff --git a/projects/Test/SequentialIntegration/SequentialIntegration.csproj b/projects/Test/SequentialIntegration/SequentialIntegration.csproj
index 474768133..dff8ad5fb 100644
--- a/projects/Test/SequentialIntegration/SequentialIntegration.csproj
+++ b/projects/Test/SequentialIntegration/SequentialIntegration.csproj
@@ -16,7 +16,7 @@
     <AssemblyOriginatorKeyFile>../../rabbit.snk</AssemblyOriginatorKeyFile>
     <SignAssembly>true</SignAssembly>
     <IsTestProject>true</IsTestProject>
-    <LangVersion>9.0</LangVersion>
+    <LangVersion>12.0</LangVersion>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/projects/Test/Unit/Unit.csproj b/projects/Test/Unit/Unit.csproj
index 9b5deb710..fc23c107a 100644
--- a/projects/Test/Unit/Unit.csproj
+++ b/projects/Test/Unit/Unit.csproj
@@ -16,7 +16,7 @@
     <AssemblyOriginatorKeyFile>../../rabbit.snk</AssemblyOriginatorKeyFile>
     <SignAssembly>true</SignAssembly>
     <IsTestProject>true</IsTestProject>
-    <LangVersion>9.0</LangVersion>
+    <LangVersion>12.0</LangVersion>
   </PropertyGroup>
 
   <ItemGroup>