diff --git a/ArduSub/mode.h b/ArduSub/mode.h
index 9907ee95b4..ba1ba46d95 100644
--- a/ArduSub/mode.h
+++ b/ArduSub/mode.h
@@ -420,7 +420,7 @@ public:
 
     bool init(bool ignore_checks) override;
 
-    bool requires_GPS() const override { return false; }
+    bool requires_GPS() const override { return true; }
     bool has_manual_throttle() const override { return false; }
     bool allows_arming(bool from_gcs) const override { return true; }
     bool is_autopilot() const override { return true; }