2 files changed, 2 insertions, 2 deletions
diff --git a/src/DotNetOpenAuth.OpenId/OpenId/Extensions/SimpleRegistration/ClaimsRequest.cs b/src/DotNetOpenAuth.OpenId/OpenId/Extensions/SimpleRegistration/ClaimsRequest.cs
index ab08cbb..f6fd620 100644
--- a/src/DotNetOpenAuth.OpenId/OpenId/Extensions/SimpleRegistration/ClaimsRequest.cs
+++ b/src/DotNetOpenAuth.OpenId/OpenId/Extensions/SimpleRegistration/ClaimsRequest.cs
@@ -9,11 +9,11 @@ namespace DotNetOpenAuth.OpenId.Extensions.SimpleRegistration {
 	using System.Collections.Generic;
 	using System.Diagnostics;
 	using System.Diagnostics.CodeAnalysis;
-	using System.Diagnostics.Contracts;
 	using System.Globalization;
 	using System.Text;
 	using DotNetOpenAuth.Messaging;
 	using DotNetOpenAuth.OpenId.Messages;
+	using Validation;
 
 	/// <summary>
 	/// Carries the request/require/none demand state of the simple registration fields.
diff --git a/src/DotNetOpenAuth.OpenId/OpenId/Extensions/SimpleRegistration/ClaimsResponse.cs b/src/DotNetOpenAuth.OpenId/OpenId/Extensions/SimpleRegistration/ClaimsResponse.cs
index af60596..361910d 100644
--- a/src/DotNetOpenAuth.OpenId/OpenId/Extensions/SimpleRegistration/ClaimsResponse.cs
+++ b/src/DotNetOpenAuth.OpenId/OpenId/Extensions/SimpleRegistration/ClaimsResponse.cs
@@ -8,7 +8,6 @@ namespace DotNetOpenAuth.OpenId.Extensions.SimpleRegistration {
 	using System;
 	using System.Collections.Generic;
 	using System.Diagnostics.CodeAnalysis;
-	using System.Diagnostics.Contracts;
 	using System.Globalization;
 	using System.Net.Mail;
 	using System.Text;
@@ -16,6 +15,7 @@ namespace DotNetOpenAuth.OpenId.Extensions.SimpleRegistration {
 	using System.Xml.Serialization;
 	using DotNetOpenAuth.Messaging;
 	using DotNetOpenAuth.OpenId.Messages;
+	using Validation;
 
 	/// <summary>
 	/// A struct storing Simple Registration field values describing an