diff --git a/libraries/AP_Compass/examples/AP_Compass_test/AP_Compass_test.pde b/libraries/AP_Compass/examples/AP_Compass_test/AP_Compass_test.pde
index 2e34fd2130..9d426f00d7 100644
--- a/libraries/AP_Compass/examples/AP_Compass_test/AP_Compass_test.pde
+++ b/libraries/AP_Compass/examples/AP_Compass_test/AP_Compass_test.pde
@@ -35,6 +35,7 @@
 #include <AP_Mission.h>
 #include <AP_Terrain.h>
 #include <AP_Rally.h>
+#include <AP_BattMonitor.h>
 
 const AP_HAL::HAL& hal = AP_HAL_BOARD_DRIVER;