diff --git a/.github/workflows/ci-build-test.yml b/.github/workflows/ci-build-test.yml
index 37ee6ab83..70e768761 100644
--- a/.github/workflows/ci-build-test.yml
+++ b/.github/workflows/ci-build-test.yml
@@ -47,15 +47,6 @@ jobs:
           10.0.x
           9.0.x
 
-    # NetFX testing on non-Windows requires mono
-    - name: 🔧 Setup Mono
-      if: runner.os == 'Linux'
-      run: sudo apt-get install -y mono-devel
-
-    - name: 🔧 Setup Mono on macOS
-      if: runner.os == 'macOS'
-      run: brew install mono
-
     - name: 🔧 Set up Node.js
       uses: actions/setup-node@6044e13b5dc448c55e2357c09f80417699197238 # v6.2.0
       with:
diff --git a/Directory.Build.props b/Directory.Build.props
index 390be36e7..f5cdd3aad 100644
--- a/Directory.Build.props
+++ b/Directory.Build.props
@@ -45,4 +45,10 @@
     <!-- Don't use x64 when running netfx test procs on Windows ARM -->
     <PreferNativeArm64>true</PreferNativeArm64>
   </PropertyGroup>
+
+  <PropertyGroup>
+    <!-- Shared target frameworks for test projects and test support projects. net472 is only included on Windows. -->
+    <DefaultTestTargetFrameworks>net10.0;net9.0;net8.0</DefaultTestTargetFrameworks>
+    <DefaultTestTargetFrameworks Condition="$([MSBuild]::IsOSPlatform('Windows'))">$(DefaultTestTargetFrameworks);net472</DefaultTestTargetFrameworks>
+  </PropertyGroup>
 </Project>
diff --git a/samples/TestServerWithHosting/TestServerWithHosting.csproj b/samples/TestServerWithHosting/TestServerWithHosting.csproj
index 7967395c0..9eca173cf 100644
--- a/samples/TestServerWithHosting/TestServerWithHosting.csproj
+++ b/samples/TestServerWithHosting/TestServerWithHosting.csproj
@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFrameworks>net10.0;net9.0;net8.0;net472</TargetFrameworks>
+    <TargetFrameworks>$(DefaultTestTargetFrameworks)</TargetFrameworks>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
     <PublishAot Condition="'$(TargetFramework)' == 'net9.0'">true</PublishAot>
diff --git a/tests/ModelContextProtocol.TestServer/ModelContextProtocol.TestServer.csproj b/tests/ModelContextProtocol.TestServer/ModelContextProtocol.TestServer.csproj
index c4b39bb54..229c57d60 100644
--- a/tests/ModelContextProtocol.TestServer/ModelContextProtocol.TestServer.csproj
+++ b/tests/ModelContextProtocol.TestServer/ModelContextProtocol.TestServer.csproj
@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFrameworks>net10.0;net9.0;net8.0;net472</TargetFrameworks>
+    <TargetFrameworks>$(DefaultTestTargetFrameworks)</TargetFrameworks>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
     <AssemblyName>TestServer</AssemblyName>
diff --git a/tests/ModelContextProtocol.Tests/ModelContextProtocol.Tests.csproj b/tests/ModelContextProtocol.Tests/ModelContextProtocol.Tests.csproj
index e0fb3d1fa..efc3527b4 100644
--- a/tests/ModelContextProtocol.Tests/ModelContextProtocol.Tests.csproj
+++ b/tests/ModelContextProtocol.Tests/ModelContextProtocol.Tests.csproj
@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFrameworks>net10.0;net9.0;net8.0;net472</TargetFrameworks>
+    <TargetFrameworks>$(DefaultTestTargetFrameworks)</TargetFrameworks>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>