diff --git a/ArduSub/Sub.h b/ArduSub/Sub.h
index 00478b8e8b..8dafad4c51 100644
--- a/ArduSub/Sub.h
+++ b/ArduSub/Sub.h
@@ -363,7 +363,7 @@ private:
 
     // terrain handling
 #if AP_TERRAIN_AVAILABLE
-    AP_Terrain terrain{mission};
+    AP_Terrain terrain;
 #endif
 
     // used to allow attitude and depth control without a position system