diff --git a/libraries/AP_Vehicle/AP_Vehicle.h b/libraries/AP_Vehicle/AP_Vehicle.h
index 81eee55e07..c6e8e2f348 100644
--- a/libraries/AP_Vehicle/AP_Vehicle.h
+++ b/libraries/AP_Vehicle/AP_Vehicle.h
@@ -74,4 +74,11 @@ public:
 #define APM_BUILD_TYPE(type) ((type) == APM_BUILD_UNKNOWN)
 #endif
 
+
+#if APM_BUILD_TYPE(APM_BUILD_APMrover2) || APM_BUILD_TYPE(APM_BUILD_ArduPlane)
+# define APM_BUILD_DELEGATES 1
+#else
+# define APM_BUILD_DELEGATES 0
+#endif
+
 #endif // AP_VEHICLE_H