diff --git a/libraries/AP_Compass/AP_Compass.cpp b/libraries/AP_Compass/AP_Compass.cpp
index 3cdd52dfcb..639df57f1a 100644
--- a/libraries/AP_Compass/AP_Compass.cpp
+++ b/libraries/AP_Compass/AP_Compass.cpp
@@ -21,7 +21,7 @@
 
 extern AP_HAL::HAL& hal;
 
-#if APM_BUILD_TYPE(APM_BUILD_ArduCopter)
+#if APM_BUILD_TYPE(APM_BUILD_ArduCopter) || APM_BUILD_TYPE(APM_BUILD_ArduSub)
 #define COMPASS_LEARN_DEFAULT Compass::LEARN_NONE
 #else
 #define COMPASS_LEARN_DEFAULT Compass::LEARN_INTERNAL