diff --git a/libraries/AP_HAL/RCOutput.h b/libraries/AP_HAL/RCOutput.h
index 68a84b1a10..dee9068138 100644
--- a/libraries/AP_HAL/RCOutput.h
+++ b/libraries/AP_HAL/RCOutput.h
@@ -376,6 +376,11 @@ public:
     */
     virtual void write_gpio(uint8_t chan, bool active) {};
 
+    /*
+      Force group trigger from all callers rather than just from the main thread
+    */
+    virtual void force_trigger_groups(bool onoff) {};
+
     /*
      * calculate the prescaler required to achieve the desire bitrate
      */