diff --git a/libraries/AP_GPS/AP_GPS_MAV.cpp b/libraries/AP_GPS/AP_GPS_MAV.cpp
index 70474a2466..b1970170ca 100644
--- a/libraries/AP_GPS/AP_GPS_MAV.cpp
+++ b/libraries/AP_GPS/AP_GPS_MAV.cpp
@@ -46,14 +46,14 @@ void AP_GPS_MAV::handle_msg(mavlink_message_t *msg)
     mavlink_gps_input_t packet;
     mavlink_msg_gps_input_decode(msg, &packet);
 
-    bool have_alt    = ((packet.ignore_flags & (1<<0)) == 0);
-    bool have_hdop   = ((packet.ignore_flags & (1<<1)) == 0);
-    bool have_vdop   = ((packet.ignore_flags & (1<<2)) == 0);
-    bool have_vel_h  = ((packet.ignore_flags & (1<<3)) == 0);
-    bool have_vel_v  = ((packet.ignore_flags & (1<<4)) == 0);
-    bool have_sa     = ((packet.ignore_flags & (1<<5)) == 0);
-    bool have_ha     = ((packet.ignore_flags & (1<<6)) == 0);
-    bool have_va     = ((packet.ignore_flags & (1<<7)) == 0);
+    bool have_alt    = ((packet.ignore_flags & GPS_INPUT_IGNORE_FLAG_ALT) == 0);
+    bool have_hdop   = ((packet.ignore_flags & GPS_INPUT_IGNORE_FLAG_HDOP) == 0);
+    bool have_vdop   = ((packet.ignore_flags & GPS_INPUT_IGNORE_FLAG_VDOP) == 0);
+    bool have_vel_h  = ((packet.ignore_flags & GPS_INPUT_IGNORE_FLAG_VEL_HORIZ) == 0);
+    bool have_vel_v  = ((packet.ignore_flags & GPS_INPUT_IGNORE_FLAG_VEL_VERT) == 0);
+    bool have_sa     = ((packet.ignore_flags & GPS_INPUT_IGNORE_FLAG_SPEED_ACCURACY) == 0);
+    bool have_ha     = ((packet.ignore_flags & GPS_INPUT_IGNORE_FLAG_HORIZONTAL_ACCURACY) == 0);
+    bool have_va     = ((packet.ignore_flags & GPS_INPUT_IGNORE_FLAG_VERTICAL_ACCURACY) == 0);
 
     state.time_week     = packet.time_week;
     state.time_week_ms  = packet.time_week_ms;