1 files changed, 12 insertions, 0 deletions
diff --git a/include/grpcpp/impl/codegen/channel_interface.h b/include/grpcpp/impl/codegen/channel_interface.h
index 6ec1ffb8c7..728a7b9049 100644
--- a/include/grpcpp/impl/codegen/channel_interface.h
+++ b/include/grpcpp/impl/codegen/channel_interface.h
@@ -53,6 +53,12 @@ template <class W, class R>
 class ClientAsyncReaderWriterFactory;
 template <class R>
 class ClientAsyncResponseReaderFactory;
+template <class W, class R>
+class ClientCallbackReaderWriterFactory;
+template <class R>
+class ClientCallbackReaderFactory;
+template <class W>
+class ClientCallbackWriterFactory;
 class InterceptedChannel;
 }  // namespace internal
 
@@ -106,6 +112,12 @@ class ChannelInterface {
   friend class ::grpc::internal::ClientAsyncReaderWriterFactory;
   template <class R>
   friend class ::grpc::internal::ClientAsyncResponseReaderFactory;
+  template <class W, class R>
+  friend class ::grpc::internal::ClientCallbackReaderWriterFactory;
+  template <class R>
+  friend class ::grpc::internal::ClientCallbackReaderFactory;
+  template <class W>
+  friend class ::grpc::internal::ClientCallbackWriterFactory;
   template <class InputMessage, class OutputMessage>
   friend class ::grpc::internal::BlockingUnaryCallImpl;
   template <class InputMessage, class OutputMessage>