diff --git a/src/modules/navigator/rtl.cpp b/src/modules/navigator/rtl.cpp
index 1a2597d877..6b80ed9b60 100644
--- a/src/modules/navigator/rtl.cpp
+++ b/src/modules/navigator/rtl.cpp
@@ -558,12 +558,14 @@ void RTL::setSafepointAsDestination(PositionYawSetpoint &rtl_position, const mis
 	// TODO: handle all possible mission_safe_point.frame cases
 	switch (mission_safe_point.frame) {
 	case 0: // MAV_FRAME_GLOBAL
+	case 5: // MAV_FRAME_GLOBAL_INT
 		rtl_position.lat = mission_safe_point.lat;
 		rtl_position.lon = mission_safe_point.lon;
-		rtl_position.alt = mission_safe_point.altitude;
+		rtl_position.alt = mission_safe_point.altitude;	// alt of safe point is relative to MSL
 		break;
 
 	case 3: // MAV_FRAME_GLOBAL_RELATIVE_ALT
+	case 6: // MAV_FRAME_GLOBAL_RELATIVE_ALT_INT
 		rtl_position.lat = mission_safe_point.lat;
 		rtl_position.lon = mission_safe_point.lon;
 		rtl_position.alt = mission_safe_point.altitude + _home_pos_sub.get().alt; // alt of safe point is rel to home