2 files changed, 1 insertions, 2 deletions
diff --git a/src/DotNetOpenAuth.OAuth.Common/OAuth/ChannelElements/OAuthIdentity.cs b/src/DotNetOpenAuth.OAuth.Common/OAuth/ChannelElements/OAuthIdentity.cs
index 1f9fbbc..28e0333 100644
--- a/src/DotNetOpenAuth.OAuth.Common/OAuth/ChannelElements/OAuthIdentity.cs
+++ b/src/DotNetOpenAuth.OAuth.Common/OAuth/ChannelElements/OAuthIdentity.cs
@@ -7,10 +7,10 @@
 namespace DotNetOpenAuth.OAuth.ChannelElements {
 	using System;
 	using System.Diagnostics.CodeAnalysis;
-	using System.Diagnostics.Contracts;
 	using System.Runtime.InteropServices;
 	using System.Security.Principal;
 	using DotNetOpenAuth.Messaging;
+	using Validation;
 
 	/// <summary>
 	/// Represents an OAuth consumer that is impersonating a known user on the system.
diff --git a/src/DotNetOpenAuth.OAuth.Common/OAuth/ChannelElements/OAuthPrincipal.cs b/src/DotNetOpenAuth.OAuth.Common/OAuth/ChannelElements/OAuthPrincipal.cs
index c23939a..65d7042 100644
--- a/src/DotNetOpenAuth.OAuth.Common/OAuth/ChannelElements/OAuthPrincipal.cs
+++ b/src/DotNetOpenAuth.OAuth.Common/OAuth/ChannelElements/OAuthPrincipal.cs
@@ -9,7 +9,6 @@ namespace DotNetOpenAuth.OAuth.ChannelElements {
 	using System.Collections.Generic;
 	using System.Collections.ObjectModel;
 	using System.Diagnostics.CodeAnalysis;
-	using System.Diagnostics.Contracts;
 	using System.Linq;
 	using System.Runtime.InteropServices;
 	using System.Security.Principal;