diff --git a/lib/csharp/test/Multiplex/Client/MultiplexClient.csproj b/lib/csharp/test/Multiplex/Client/MultiplexClient.csproj
index 6221e14..ff78723 100644
--- a/lib/csharp/test/Multiplex/Client/MultiplexClient.csproj
+++ b/lib/csharp/test/Multiplex/Client/MultiplexClient.csproj
@@ -28,7 +28,7 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>MultiplexClient</RootNamespace>
     <AssemblyName>MultiplexClient</AssemblyName>
-    <TargetFrameworkVersion>v3.5</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <IsWebBootstrapper>false</IsWebBootstrapper>
     <FileUpgradeFlags>
diff --git a/lib/csharp/test/Multiplex/Server/MultiplexServer.csproj b/lib/csharp/test/Multiplex/Server/MultiplexServer.csproj
index dc1d123..6a8177e 100644
--- a/lib/csharp/test/Multiplex/Server/MultiplexServer.csproj
+++ b/lib/csharp/test/Multiplex/Server/MultiplexServer.csproj
@@ -28,7 +28,7 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>MultiplexServer</RootNamespace>
     <AssemblyName>MultiplexServer</AssemblyName>
-    <TargetFrameworkVersion>v3.5</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <IsWebBootstrapper>false</IsWebBootstrapper>
     <FileUpgradeFlags>