diff --git a/libraries/AC_Sprayer/examples/AC_Sprayer_test/AC_Sprayer_test.pde b/libraries/AC_Sprayer/examples/AC_Sprayer_test/AC_Sprayer_test.pde
index d965a35a51..fbe35f83b3 100644
--- a/libraries/AC_Sprayer/examples/AC_Sprayer_test/AC_Sprayer_test.pde
+++ b/libraries/AC_Sprayer/examples/AC_Sprayer_test/AC_Sprayer_test.pde
@@ -29,6 +29,7 @@
 #include <DataFlash.h>
 #include <GCS_MAVLink.h>
 #include <AP_Mission.h>
+#include <AP_Terrain.h>
 #include <RC_Channel.h>
 #include <AC_Sprayer.h>         // Crop Sprayer library
 #include <AP_Notify.h>