diff --git a/sw/airborne/main_ap.c b/sw/airborne/main_ap.c
index ba705e2670..3f53cc41fb 100644
--- a/sw/airborne/main_ap.c
+++ b/sw/airborne/main_ap.c
@@ -497,6 +497,11 @@ void periodic_task_ap( void ) {
 
   switch(_4Hz) {
   case 0:
+#ifdef SITL
+#ifdef GPS_TRIGGERED_FUNCTION
+	GPS_TRIGGERED_FUNCTION();
+#endif
+#endif
     estimator_propagate_state();
     navigation_task();
     break;
@@ -906,13 +911,16 @@ void event_task_ap( void ) {
       UseGpsPosNoSend(estimator_update_state_gps);
       gps_downlink();
 #ifdef GPS_TRIGGERED_FUNCTION
+#ifndef SITL
 	GPS_TRIGGERED_FUNCTION();
+#endif
 #endif
       gps_pos_available = FALSE;
     }
   }
 #endif /** GPS */
 
+
 #if defined DATALINK 
 
 #if DATALINK == PPRZ