diff --git a/libraries/AP_Vehicle/AP_Vehicle_Type.h b/libraries/AP_Vehicle/AP_Vehicle_Type.h
index ead078e626..af01c6cc2e 100644
--- a/libraries/AP_Vehicle/AP_Vehicle_Type.h
+++ b/libraries/AP_Vehicle/AP_Vehicle_Type.h
@@ -27,6 +27,7 @@
 #define APM_BUILD_AntennaTracker 4
 #define APM_BUILD_UNKNOWN        5
 #define APM_BUILD_Replay         6
+#define APM_BUILD_ArduSub        7
 
 /*
   using this macro catches cases where we try to check vehicle type on