diff --git a/libraries/GCS_MAVLink/GCS_Common.cpp b/libraries/GCS_MAVLink/GCS_Common.cpp
index c1f07fea17c82..90c6eb88e99d6 100644
--- a/libraries/GCS_MAVLink/GCS_Common.cpp
+++ b/libraries/GCS_MAVLink/GCS_Common.cpp
@@ -2600,19 +2600,7 @@ void GCS_MAVLINK::handle_set_mode(const mavlink_message_t &msg)
     const MAV_MODE _base_mode = (MAV_MODE)packet.base_mode;
     const uint32_t _custom_mode = packet.custom_mode;
 
-    const MAV_RESULT result = _set_mode_common(_base_mode, _custom_mode);
-
-    // send ACK or NAK.  Note that this is extraodinarily improper -
-    // we are sending a command-ack for a message which is not a
-    // command.  The command we are acking (ID=11) doesn't actually
-    // exist, but if it did we'd probably be acking something
-    // completely unrelated to setting modes.
-    if (HAVE_PAYLOAD_SPACE(chan, COMMAND_ACK)) {
-        mavlink_msg_command_ack_send(chan, MAVLINK_MSG_ID_SET_MODE, result,
-                                     0, 0,
-                                     msg.sysid,
-                                     msg.compid);
-    }
+    _set_mode_common(_base_mode, _custom_mode);
 }
 
 /*