1 files changed, 12 insertions, 1 deletions
diff --git a/include/grpc++/async_unary_call.h b/include/grpc++/async_unary_call.h
index d1d5be5b50..97cec77955 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,