1 files changed, 1 insertions, 1 deletions
diff --git a/src/DotNetOpenAuth.OpenId.RelyingParty/OpenId/RelyingParty/AssociationManager.cs b/src/DotNetOpenAuth.OpenId.RelyingParty/OpenId/RelyingParty/AssociationManager.cs
index e6feac1..dfb307b 100644
--- a/src/DotNetOpenAuth.OpenId.RelyingParty/OpenId/RelyingParty/AssociationManager.cs
+++ b/src/DotNetOpenAuth.OpenId.RelyingParty/OpenId/RelyingParty/AssociationManager.cs
@@ -7,7 +7,6 @@
 namespace DotNetOpenAuth.OpenId.RelyingParty {
 	using System;
 	using System.Collections.Generic;
-	using System.Diagnostics.Contracts;
 	using System.Linq;
 	using System.Net;
 	using System.Security;
@@ -15,6 +14,7 @@ namespace DotNetOpenAuth.OpenId.RelyingParty {
 	using DotNetOpenAuth.Messaging;
 	using DotNetOpenAuth.OpenId.ChannelElements;
 	using DotNetOpenAuth.OpenId.Messages;
+	using Validation;
 
 	/// <summary>
 	/// Manages the establishment, storage and retrieval of associations at the relying party.