diff --git a/src/ProtoGen/ServiceInterfaceGenerator.cs b/src/ProtoGen/ServiceInterfaceGenerator.cs
index 4e31dcf2f0..fe0a8b4acc 100644
--- a/src/ProtoGen/ServiceInterfaceGenerator.cs
+++ b/src/ProtoGen/ServiceInterfaceGenerator.cs
@@ -274,7 +274,7 @@ namespace Google.ProtocolBuffers.ProtoGen
                     writer.WriteLine();
 
                     writer.WriteLine(
-                        "public pb::IMessageLite CallMethod(string methodName, pb::CodedInputStream input, pb::ExtensionRegistry registry) {{",
+                        "public pb::IMessageLite CallMethod(string methodName, pb::ICodedInputStream input, pb::ExtensionRegistry registry) {{",
                         Descriptor.Name);
                     writer.Indent();
                     writer.WriteLine("switch(methodName) {");
diff --git a/src/ProtocolBuffers.Test/TestProtos/UnitTestRpcInterop.cs b/src/ProtocolBuffers.Test/TestProtos/UnitTestRpcInterop.cs
index f5fa46e553..df5d30767f 100644
--- a/src/ProtocolBuffers.Test/TestProtos/UnitTestRpcInterop.cs
+++ b/src/ProtocolBuffers.Test/TestProtos/UnitTestRpcInterop.cs
@@ -1305,7 +1305,7 @@ namespace Google.ProtocolBuffers.TestProtos {
         if (dispose) ((global::System.IDisposable)implementation).Dispose();
       }
       
-      public pb::IMessageLite CallMethod(string methodName, pb::CodedInputStream input, pb::ExtensionRegistry registry) {
+      public pb::IMessageLite CallMethod(string methodName, pb::ICodedInputStream input, pb::ExtensionRegistry registry) {
         switch(methodName) {
           case "Search": return implementation.CallMethod(methodName, global::Google.ProtocolBuffers.TestProtos.SearchRequest.ParseFrom(input, registry), global::Google.ProtocolBuffers.TestProtos.SearchResponse.CreateBuilder());
           case "RefineSearch": return implementation.CallMethod(methodName, global::Google.ProtocolBuffers.TestProtos.RefineSearchRequest.ParseFrom(input, registry), global::Google.ProtocolBuffers.TestProtos.SearchResponse.CreateBuilder());
diff --git a/src/ProtocolBuffers/DynamicMessage.cs b/src/ProtocolBuffers/DynamicMessage.cs
index cd874a70f4..22bcdeb782 100644
--- a/src/ProtocolBuffers/DynamicMessage.cs
+++ b/src/ProtocolBuffers/DynamicMessage.cs
@@ -77,7 +77,7 @@ namespace Google.ProtocolBuffers
         /// <summary>
         /// Parses a message of the given type from the given stream.
         /// </summary>
-        public static DynamicMessage ParseFrom(MessageDescriptor type, CodedInputStream input)
+        public static DynamicMessage ParseFrom(MessageDescriptor type, ICodedInputStream input)
         {
             Builder builder = CreateBuilder(type);
             Builder dynamicBuilder = builder.MergeFrom(input);
@@ -91,7 +91,7 @@ namespace Google.ProtocolBuffers
         /// <param name="input"></param>
         /// <param name="extensionRegistry"></param>
         /// <returns></returns>
-        public static DynamicMessage ParseFrom(MessageDescriptor type, CodedInputStream input,
+        public static DynamicMessage ParseFrom(MessageDescriptor type, ICodedInputStream input,
                                                ExtensionRegistry extensionRegistry)
         {
             Builder builder = CreateBuilder(type);
diff --git a/src/ProtocolBuffers/IRpcDispatch.cs b/src/ProtocolBuffers/IRpcDispatch.cs
index 5abe4f87db..0583d47272 100644
--- a/src/ProtocolBuffers/IRpcDispatch.cs
+++ b/src/ProtocolBuffers/IRpcDispatch.cs
@@ -43,7 +43,7 @@ namespace Google.ProtocolBuffers
     /// </summary>
     public interface IRpcServerStub
     {
-        IMessageLite CallMethod(string methodName, CodedInputStream input, ExtensionRegistry registry);
+        IMessageLite CallMethod(string methodName, ICodedInputStream input, ExtensionRegistry registry);
     }
 
     public interface IRpcDispatch