1 files changed, 1 insertions, 1 deletions
diff --git a/src/DotNetOpenAuth.OpenId/OpenId/Messages/IndirectResponseBase.cs b/src/DotNetOpenAuth.OpenId/OpenId/Messages/IndirectResponseBase.cs
index ae0217d..cd56175 100644
--- a/src/DotNetOpenAuth.OpenId/OpenId/Messages/IndirectResponseBase.cs
+++ b/src/DotNetOpenAuth.OpenId/OpenId/Messages/IndirectResponseBase.cs
@@ -7,10 +7,10 @@
 namespace DotNetOpenAuth.OpenId.Messages {
 	using System;
 	using System.Collections.Generic;
-	using System.Diagnostics.Contracts;
 	using System.Linq;
 	using System.Text;
 	using DotNetOpenAuth.Messaging;
+	using Validation;
 
 	/// <summary>
 	/// A common base class from which indirect response messages should derive.