diff --git a/ArduCopter/Copter.cpp b/ArduCopter/Copter.cpp
index 8914d5a4ef670..0f263b89c0621 100644
--- a/ArduCopter/Copter.cpp
+++ b/ArduCopter/Copter.cpp
@@ -448,6 +448,10 @@ AP_Vehicle::custom_mode_state* Copter::register_custom_mode(const uint8_t num, c
                 // Allocation failure
                 return nullptr;
             }
+
+            // Registration sucsessful, notify the GCS that it should re-request the avalable modes
+            gcs().available_modes_changed();
+
             return &mode_guided_custom[i]->state;
         }
     }