diff --git a/X10D/src/Collections/DictionaryExtensions.cs b/X10D/src/Collections/DictionaryExtensions.cs
index 867e348..f2594a0 100644
--- a/X10D/src/Collections/DictionaryExtensions.cs
+++ b/X10D/src/Collections/DictionaryExtensions.cs
@@ -1,5 +1,4 @@
-using System.Collections.Generic;
-using System.Diagnostics.Contracts;
+using System.Diagnostics.Contracts;
 using System.Runtime.InteropServices;
 using System.Web;