diff --git a/include/grpc++/impl/proto_utils.h b/include/grpc++/impl/proto_utils.h
index 3d9a5488520083fd27556b3ed60f70f4c262ba5c..ebefa3e1bec6244692e33a18ec8843cbe23dba20 100644
--- a/include/grpc++/impl/proto_utils.h
+++ b/include/grpc++/impl/proto_utils.h
@@ -41,8 +41,6 @@
 #include <grpc++/config_protobuf.h>
 #include <grpc++/status.h>
 
-struct grpc_byte_buffer;
-
 namespace grpc {
 
 // Serialize the msg into a buffer created inside the function. The caller
diff --git a/include/grpc++/impl/serialization_traits.h b/include/grpc++/impl/serialization_traits.h
index ad61dc2f6a3c46b5e344005e44dac8d6eff3115d..1f5c674e4ca1839db5b78a6722b05ec76150e010 100644
--- a/include/grpc++/impl/serialization_traits.h
+++ b/include/grpc++/impl/serialization_traits.h
@@ -34,8 +34,6 @@
 #ifndef GRPCXX_IMPL_SERIALIZATION_TRAITS_H
 #define GRPCXX_IMPL_SERIALIZATION_TRAITS_H
 
-struct grpc_byte_buffer;
-
 namespace grpc {
 
 /// Defines how to serialize and deserialize some type.