diff --git a/include/libnuraft/async.hxx b/include/libnuraft/async.hxx
index 872db482..1ead4de8 100644
--- a/include/libnuraft/async.hxx
+++ b/include/libnuraft/async.hxx
@@ -36,7 +36,7 @@ limitations under the License.
 
 namespace nuraft {
 
-enum cmd_result_code {
+enum cmd_result_code : int32_t {
     OK                              =  0,
     CANCELLED                       = -1,
     TIMEOUT                         = -2,
diff --git a/src/asio_service.cxx b/src/asio_service.cxx
index ff84ce86..f8f2d4f3 100644
--- a/src/asio_service.cxx
+++ b/src/asio_service.cxx
@@ -124,6 +124,9 @@ limitations under the License.
 // If set, each log entry will contain a CRC on the payload.
 #define CRC_ON_PAYLOAD (0x10)
 
+// If set, RPC message (response) includes result code
+#define INCLUDE_RESULT_CODE (0x20)
+
 // =======================
 
 namespace nuraft {
@@ -735,6 +738,7 @@ class rpc_session
        try {
         ptr<buffer> resp_ctx = resp->get_ctx();
         int32 resp_ctx_size = (resp_ctx) ? resp_ctx->size() : 0;
+        int32 result_code_size = sizeof(int32_t);
 
         uint32_t flags = 0x0;
         size_t resp_meta_size = 0;
@@ -759,6 +763,13 @@ class rpc_session
 
         size_t carried_data_size = resp_meta_size + resp_hint_size + resp_ctx_size;
 
+        if (req->get_type() == msg_type::client_request ||
+            req->get_type() == msg_type::add_server_request ||
+            req->get_type() == msg_type::remove_server_request) {
+            flags |= INCLUDE_RESULT_CODE;
+            carried_data_size += result_code_size;
+        }
+
         int buf_size = RPC_RESP_HEADER_SIZE + carried_data_size;
         ptr<buffer> resp_buf = buffer::alloc(buf_size);
         buffer_serializer bs(resp_buf);
@@ -798,6 +809,11 @@ class rpc_session
             bs.put_buffer(*resp_ctx);
         }
 
+        /* Put result code at the end to avoid breaking backward compatibility */
+        if (flags & INCLUDE_RESULT_CODE) {
+            bs.put_i32(resp->get_result_code());
+        }
+
         aa::write( ssl_enabled_, ssl_socket_, socket_,
                    asio::buffer(resp_buf->data_begin(), resp_buf->size()),
                    [this, self, resp_buf]
@@ -1688,8 +1704,9 @@ class asio_rpc_client
                   size_t bytes_transferred)
     {
         if ( !(flags & INCLUDE_META) &&
-             !(flags & INCLUDE_HINT) ) {
-            // Neither meta nor hint exists,
+             !(flags & INCLUDE_HINT) &&
+	     !(flags & INCLUDE_RESULT_CODE)) {
+            // Neither meta nor hint nor result code exists,
             // just use the buffer as it is for ctx.
             ctx_buf->pos(0);
             rsp->set_ctx(ctx_buf);
@@ -1739,9 +1756,21 @@ class asio_rpc_client
         assert(remaining_len >= 0);
         if (remaining_len) {
             // It has context, read it.
-            ptr<buffer> actual_ctx = buffer::alloc(remaining_len);
+            size_t ctx_len = remaining_len;
+            if (flags & INCLUDE_RESULT_CODE) {
+                ctx_len -= sizeof(int32_t);
+            }
+            ptr<buffer> actual_ctx = buffer::alloc(ctx_len);
             bs.get_buffer(actual_ctx);
             rsp->set_ctx(actual_ctx);
+            remaining_len -= ctx_len;
+        }
+
+        // 4) Result code
+        if (flags & INCLUDE_RESULT_CODE) {
+            assert((size_t)remaining_len >= sizeof(int32_t));
+            cmd_result_code res = static_cast<cmd_result_code>(bs.get_i32());
+            rsp->set_result_code(res);
         }
 
         operation_timer_.cancel();