diff --git a/libraries/AP_Vehicle/AP_Vehicle.h b/libraries/AP_Vehicle/AP_Vehicle.h
index ffa70eec6d..f56262e0c3 100644
--- a/libraries/AP_Vehicle/AP_Vehicle.h
+++ b/libraries/AP_Vehicle/AP_Vehicle.h
@@ -247,8 +247,11 @@ public:
     // returns true on success and control_value is set to a value in the range -1 to +1
     virtual bool get_control_output(AP_Vehicle::ControlOutput control_output, float &control_value) { return false; }
 
-    // Register a custom mode with given number and names
-    virtual bool register_custom_mode(const uint8_t number, const char* full_name, const char* short_name) { return false; }
+    // Register a custom mode with given number and names, return a structure which the script can edit
+    struct custom_mode_state {
+        bool allow_entry;
+    };
+    virtual custom_mode_state* register_custom_mode(const uint8_t number, const char* full_name, const char* short_name) { return nullptr; }
 
 #endif // AP_SCRIPTING_ENABLED