diff --git a/include/grpc++/async_unary_call.h b/include/grpc++/async_unary_call.h
index d1d5be5b50e..97cec77955c 100644
--- a/include/grpc++/async_unary_call.h
+++ b/include/grpc++/async_unary_call.h
@@ -44,8 +44,19 @@
 #include <grpc/support/log.h>
 
 namespace grpc {
+
+template <class R>
+class ClientAsyncResponseReaderInterface {
+ public:
+  virtual ~ClientAsyncResponseReaderInterface() {}
+  virtual void ReadInitialMetadata(void* tag) = 0;
+  virtual void Finish(R* msg, Status* status, void* tag) = 0;
+
+};
+
 template <class R>
-class ClientAsyncResponseReader GRPC_FINAL {
+class ClientAsyncResponseReader GRPC_FINAL
+    : public ClientAsyncResponseReaderInterface<R> {
  public:
   ClientAsyncResponseReader(ChannelInterface* channel, CompletionQueue* cq,
                             const RpcMethod& method, ClientContext* context,
diff --git a/include/grpc++/stream.h b/include/grpc++/stream.h
index 6647e345c0c..0efdbdaecae 100644
--- a/include/grpc++/stream.h
+++ b/include/grpc++/stream.h
@@ -83,8 +83,14 @@ class WriterInterface {
 };
 
 template <class R>
-class ClientReader GRPC_FINAL : public ClientStreamingInterface,
-                                public ReaderInterface<R> {
+class ClientReaderInterface : public ClientStreamingInterface,
+                              public ReaderInterface<R> {
+ public:
+  virtual void WaitForInitialMetadata() = 0;
+};
+
+template <class R>
+class ClientReader GRPC_FINAL : public ClientReaderInterface<R> {
  public:
   // Blocking create a stream and write the first request out.
   ClientReader(ChannelInterface* channel, const RpcMethod& method,
@@ -111,7 +117,7 @@ class ClientReader GRPC_FINAL : public ClientStreamingInterface,
     GPR_ASSERT(cq_.Pluck(&buf));
   }
 
-  virtual bool Read(R* msg) GRPC_OVERRIDE {
+  bool Read(R* msg) GRPC_OVERRIDE {
     CallOpBuffer buf;
     if (!context_->initial_metadata_received_) {
       buf.AddRecvInitialMetadata(context_);
@@ -121,7 +127,7 @@ class ClientReader GRPC_FINAL : public ClientStreamingInterface,
     return cq_.Pluck(&buf) && buf.got_message;
   }
 
-  virtual Status Finish() GRPC_OVERRIDE {
+  Status Finish() GRPC_OVERRIDE {
     CallOpBuffer buf;
     Status status;
     buf.AddClientRecvStatus(context_, &status);
@@ -137,8 +143,14 @@ class ClientReader GRPC_FINAL : public ClientStreamingInterface,
 };
 
 template <class W>
-class ClientWriter GRPC_FINAL : public ClientStreamingInterface,
-                                public WriterInterface<W> {
+class ClientWriterInterface : public ClientStreamingInterface,
+                              public WriterInterface<W> {
+ public:
+  virtual bool WritesDone() = 0;
+};
+
+template <class W>
+class ClientWriter GRPC_FINAL : public ClientWriterInterface<W> {
  public:
   // Blocking create a stream.
   ClientWriter(ChannelInterface* channel, const RpcMethod& method,
@@ -152,14 +164,14 @@ class ClientWriter GRPC_FINAL : public ClientStreamingInterface,
     cq_.Pluck(&buf);
   }
 
-  virtual bool Write(const W& msg) GRPC_OVERRIDE {
+  bool Write(const W& msg) GRPC_OVERRIDE {
     CallOpBuffer buf;
     buf.AddSendMessage(msg);
     call_.PerformOps(&buf);
     return cq_.Pluck(&buf);
   }
 
-  virtual bool WritesDone() {
+  bool WritesDone() GRPC_OVERRIDE {
     CallOpBuffer buf;
     buf.AddClientSendClose();
     call_.PerformOps(&buf);
@@ -167,7 +179,7 @@ class ClientWriter GRPC_FINAL : public ClientStreamingInterface,
   }
 
   // Read the final response and wait for the final status.
-  virtual Status Finish() GRPC_OVERRIDE {
+  Status Finish() GRPC_OVERRIDE {
     CallOpBuffer buf;
     Status status;
     buf.AddRecvMessage(response_);
@@ -186,9 +198,16 @@ class ClientWriter GRPC_FINAL : public ClientStreamingInterface,
 
 // Client-side interface for bi-directional streaming.
 template <class W, class R>
-class ClientReaderWriter GRPC_FINAL : public ClientStreamingInterface,
-                                      public WriterInterface<W>,
-                                      public ReaderInterface<R> {
+class ClientReaderWriterInterface : public ClientStreamingInterface,
+                                    public WriterInterface<W>,
+                                    public ReaderInterface<R> {
+ public:
+  virtual void WaitForInitialMetadata() = 0;
+  virtual bool WritesDone() = 0;
+};
+
+template <class W, class R>
+class ClientReaderWriter GRPC_FINAL : public ClientReaderWriterInterface<W, R> {
  public:
   // Blocking create a stream.
   ClientReaderWriter(ChannelInterface* channel, const RpcMethod& method,
@@ -213,7 +232,7 @@ class ClientReaderWriter GRPC_FINAL : public ClientStreamingInterface,
     GPR_ASSERT(cq_.Pluck(&buf));
   }
 
-  virtual bool Read(R* msg) GRPC_OVERRIDE {
+  bool Read(R* msg) GRPC_OVERRIDE {
     CallOpBuffer buf;
     if (!context_->initial_metadata_received_) {
       buf.AddRecvInitialMetadata(context_);
@@ -223,21 +242,21 @@ class ClientReaderWriter GRPC_FINAL : public ClientStreamingInterface,
     return cq_.Pluck(&buf) && buf.got_message;
   }
 
-  virtual bool Write(const W& msg) GRPC_OVERRIDE {
+  bool Write(const W& msg) GRPC_OVERRIDE {
     CallOpBuffer buf;
     buf.AddSendMessage(msg);
     call_.PerformOps(&buf);
     return cq_.Pluck(&buf);
   }
 
-  virtual bool WritesDone() {
+  bool WritesDone() GRPC_OVERRIDE {
     CallOpBuffer buf;
     buf.AddClientSendClose();
     call_.PerformOps(&buf);
     return cq_.Pluck(&buf);
   }
 
-  virtual Status Finish() GRPC_OVERRIDE {
+  Status Finish() GRPC_OVERRIDE {
     CallOpBuffer buf;
     Status status;
     buf.AddClientRecvStatus(context_, &status);
@@ -267,7 +286,7 @@ class ServerReader GRPC_FINAL : public ReaderInterface<R> {
     call_->cq()->Pluck(&buf);
   }
 
-  virtual bool Read(R* msg) GRPC_OVERRIDE {
+  bool Read(R* msg) GRPC_OVERRIDE {
     CallOpBuffer buf;
     buf.AddRecvMessage(msg);
     call_->PerformOps(&buf);
@@ -294,7 +313,7 @@ class ServerWriter GRPC_FINAL : public WriterInterface<W> {
     call_->cq()->Pluck(&buf);
   }
 
-  virtual bool Write(const W& msg) GRPC_OVERRIDE {
+  bool Write(const W& msg) GRPC_OVERRIDE {
     CallOpBuffer buf;
     if (!ctx_->sent_initial_metadata_) {
       buf.AddSendInitialMetadata(&ctx_->initial_metadata_);
@@ -327,14 +346,14 @@ class ServerReaderWriter GRPC_FINAL : public WriterInterface<W>,
     call_->cq()->Pluck(&buf);
   }
 
-  virtual bool Read(R* msg) GRPC_OVERRIDE {
+  bool Read(R* msg) GRPC_OVERRIDE {
     CallOpBuffer buf;
     buf.AddRecvMessage(msg);
     call_->PerformOps(&buf);
     return call_->cq()->Pluck(&buf) && buf.got_message;
   }
 
-  virtual bool Write(const W& msg) GRPC_OVERRIDE {
+  bool Write(const W& msg) GRPC_OVERRIDE {
     CallOpBuffer buf;
     if (!ctx_->sent_initial_metadata_) {
       buf.AddSendInitialMetadata(&ctx_->initial_metadata_);
@@ -380,8 +399,12 @@ class AsyncWriterInterface {
 };
 
 template <class R>
-class ClientAsyncReader GRPC_FINAL : public ClientAsyncStreamingInterface,
-                                     public AsyncReaderInterface<R> {
+class ClientAsyncReaderInterface : public ClientAsyncStreamingInterface,
+                                   public AsyncReaderInterface<R> {
+};
+
+template <class R>
+class ClientAsyncReader GRPC_FINAL : public ClientAsyncReaderInterface<R> {
  public:
   // Create a stream and write the first request out.
   ClientAsyncReader(ChannelInterface* channel, CompletionQueue* cq,
@@ -431,8 +454,14 @@ class ClientAsyncReader GRPC_FINAL : public ClientAsyncStreamingInterface,
 };
 
 template <class W>
-class ClientAsyncWriter GRPC_FINAL : public ClientAsyncStreamingInterface,
-                                     public AsyncWriterInterface<W> {
+class ClientAsyncWriterInterface : public ClientAsyncStreamingInterface,
+                                   public AsyncWriterInterface<W> {
+ public:
+  virtual void WritesDone(void* tag) = 0;
+};
+
+template <class W>
+class ClientAsyncWriter GRPC_FINAL : public ClientAsyncWriterInterface<W> {
  public:
   ClientAsyncWriter(ChannelInterface* channel, CompletionQueue* cq,
                     const RpcMethod& method, ClientContext* context,
@@ -459,7 +488,7 @@ class ClientAsyncWriter GRPC_FINAL : public ClientAsyncStreamingInterface,
     call_.PerformOps(&write_buf_);
   }
 
-  void WritesDone(void* tag) {
+  void WritesDone(void* tag) GRPC_OVERRIDE {
     writes_done_buf_.Reset(tag);
     writes_done_buf_.AddClientSendClose();
     call_.PerformOps(&writes_done_buf_);
@@ -488,9 +517,16 @@ class ClientAsyncWriter GRPC_FINAL : public ClientAsyncStreamingInterface,
 
 // Client-side interface for bi-directional streaming.
 template <class W, class R>
-class ClientAsyncReaderWriter GRPC_FINAL : public ClientAsyncStreamingInterface,
-                                           public AsyncWriterInterface<W>,
-                                           public AsyncReaderInterface<R> {
+class ClientAsyncReaderWriterInterface : public ClientAsyncStreamingInterface,
+                                         public AsyncWriterInterface<W>,
+                                         public AsyncReaderInterface<R> {
+ public:
+  virtual void WritesDone(void* tag) = 0;
+};
+
+template <class W, class R>
+class ClientAsyncReaderWriter GRPC_FINAL
+    : public ClientAsyncReaderWriterInterface<W, R> {
  public:
   ClientAsyncReaderWriter(ChannelInterface* channel, CompletionQueue* cq,
                           const RpcMethod& method, ClientContext* context,
@@ -524,7 +560,7 @@ class ClientAsyncReaderWriter GRPC_FINAL : public ClientAsyncStreamingInterface,
     call_.PerformOps(&write_buf_);
   }
 
-  void WritesDone(void* tag) {
+  void WritesDone(void* tag) GRPC_OVERRIDE {
     writes_done_buf_.Reset(tag);
     writes_done_buf_.AddClientSendClose();
     call_.PerformOps(&writes_done_buf_);
@@ -671,13 +707,13 @@ class ServerAsyncReaderWriter GRPC_FINAL : public ServerAsyncStreamingInterface,
     call_.PerformOps(&meta_buf_);
   }
 
-  virtual void Read(R* msg, void* tag) GRPC_OVERRIDE {
+  void Read(R* msg, void* tag) GRPC_OVERRIDE {
     read_buf_.Reset(tag);
     read_buf_.AddRecvMessage(msg);
     call_.PerformOps(&read_buf_);
   }
 
-  virtual void Write(const W& msg, void* tag) GRPC_OVERRIDE {
+  void Write(const W& msg, void* tag) GRPC_OVERRIDE {
     write_buf_.Reset(tag);
     if (!ctx_->sent_initial_metadata_) {
       write_buf_.AddSendInitialMetadata(&ctx_->initial_metadata_);