diff --git a/Src/Newtonsoft.Json/Utilities/DynamicUtils.cs b/Src/Newtonsoft.Json/Utilities/DynamicUtils.cs
index 92e338ed..ca5b3308 100644
--- a/Src/Newtonsoft.Json/Utilities/DynamicUtils.cs
+++ b/Src/Newtonsoft.Json/Utilities/DynamicUtils.cs
@@ -16,10 +16,16 @@ namespace Newtonsoft.Json.Utilities
   {
     internal static class BinderWrapper
     {
-      private const string BinderTypeName = "Microsoft.CSharp.RuntimeBinder.Binder, Microsoft.CSharp, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a";
-      private const string CSharpArgumentInfoTypeName = "Microsoft.CSharp.RuntimeBinder.CSharpArgumentInfo, Microsoft.CSharp, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a";
-      private const string CSharpArgumentInfoFlagsTypeName = "Microsoft.CSharp.RuntimeBinder.CSharpArgumentInfoFlags, Microsoft.CSharp, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a";
-      private const string CSharpBinderFlagsTypeName = "Microsoft.CSharp.RuntimeBinder.CSharpBinderFlags, Microsoft.CSharp, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a";
+#if !SILVERLIGHT
+      public const string CSharpAssemblyName = "Microsoft.CSharp, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a";
+#else
+      public const string CSharpAssemblyName = "Microsoft.CSharp, Version=2.0.5.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35";
+#endif
+
+      private const string BinderTypeName = "Microsoft.CSharp.RuntimeBinder.Binder, " + CSharpAssemblyName;
+      private const string CSharpArgumentInfoTypeName = "Microsoft.CSharp.RuntimeBinder.CSharpArgumentInfo, " + CSharpAssemblyName;
+      private const string CSharpArgumentInfoFlagsTypeName = "Microsoft.CSharp.RuntimeBinder.CSharpArgumentInfoFlags, " + CSharpAssemblyName;
+      private const string CSharpBinderFlagsTypeName = "Microsoft.CSharp.RuntimeBinder.CSharpBinderFlags, " + CSharpAssemblyName;
 
       private static object _getCSharpArgumentInfoArray;
       private static object _setCSharpArgumentInfoArray;