Merge branch 'retargeting-contracts'

1 files changed, 2 insertions, 2 deletions

diff --git a/src/DotNetOpenAuth.OAuth2.ResourceServer/OAuth2/ResourceServer.cs b/src/DotNetOpenAuth.OAuth2.ResourceServer/OAuth2/ResourceServer.cs
index 896588f..540773f 100644
--- a/src/DotNetOpenAuth.OAuth2.ResourceServer/OAuth2/ResourceServer.cs
+++ b/src/DotNetOpenAuth.OAuth2.ResourceServer/OAuth2/ResourceServer.cs
@@ -8,7 +8,6 @@ namespace DotNetOpenAuth.OAuth2 {
 	using System;
 	using System.Collections.Generic;
 	using System.Diagnostics.CodeAnalysis;
-	using System.Diagnostics.Contracts;
 	using System.Linq;
 	using System.Net;
 #if CLR4
@@ -23,6 +22,7 @@ namespace DotNetOpenAuth.OAuth2 {
 	using DotNetOpenAuth.OAuth.ChannelElements;
 	using Messages;
 	using Messaging;
+	using Validation;
 
 	/// <summary>
 	/// Provides services for validating OAuth access tokens.
@@ -90,7 +90,7 @@ namespace DotNetOpenAuth.OAuth2 {
 		/// </exception>
 		public virtual AccessToken GetAccessToken(HttpRequestBase httpRequestInfo = null, params string[] requiredScopes) {
 			Requires.NotNull(requiredScopes, "requiredScopes");
-			Requires.ValidState(this.ScopeSatisfiedCheck != null, Strings.RequiredPropertyNotYetPreset);
+			RequiresEx.ValidState(this.ScopeSatisfiedCheck != null, Strings.RequiredPropertyNotYetPreset);
 			if (httpRequestInfo == null) {
 				httpRequestInfo = this.Channel.GetRequestFromContext();
 			}