diff --git a/libraries/AP_Mount/AP_Mount_Backend.cpp b/libraries/AP_Mount/AP_Mount_Backend.cpp
index a654015a12..2f89d4f2a2 100644
--- a/libraries/AP_Mount/AP_Mount_Backend.cpp
+++ b/libraries/AP_Mount/AP_Mount_Backend.cpp
@@ -162,7 +162,7 @@ void AP_Mount_Backend::send_gimbal_manager_information(mavlink_channel_t chan)
     mavlink_msg_gimbal_manager_information_send(chan,
                                                 AP_HAL::millis(),                       // autopilot system time
                                                 get_gimbal_manager_capability_flags(),  // bitmap of gimbal manager capability flags
-                                                _instance,                              // gimbal device id
+                                                _instance + 1,                          // gimbal device id
                                                 radians(_params.roll_angle_min),        // roll_min in radians
                                                 radians(_params.roll_angle_max),        // roll_max in radians
                                                 radians(_params.pitch_angle_min),       // pitch_min in radians