diff --git a/libraries/AP_GPS/examples/GPS_AUTO_test/GPS_AUTO_test.pde b/libraries/AP_GPS/examples/GPS_AUTO_test/GPS_AUTO_test.pde
index 223a1cd8f18d8f70a845af3e72bd74b3a64f469d..f5edc99f784e1071638860f7ec7d633e10c9b319 100644
--- a/libraries/AP_GPS/examples/GPS_AUTO_test/GPS_AUTO_test.pde
+++ b/libraries/AP_GPS/examples/GPS_AUTO_test/GPS_AUTO_test.pde
@@ -30,6 +30,7 @@
 #include <AP_Math.h>
 #include <AP_Notify.h>
 #include <AP_BoardLED.h>
+#include <AP_NavEKF.h>
 
 const AP_HAL::HAL& hal = AP_HAL_BOARD_DRIVER;