diff --git a/ArduSub/AP_Arming_Sub.h b/ArduSub/AP_Arming_Sub.h
index 1454862cc9..d89977f3ca 100644
--- a/ArduSub/AP_Arming_Sub.h
+++ b/ArduSub/AP_Arming_Sub.h
@@ -14,7 +14,7 @@ public:
     AP_Arming_Sub(const AP_Arming_Sub &other) = delete;
     AP_Arming_Sub &operator=(const AP_Baro&) = delete;
 
-    bool rc_calibration_checks(bool report=true) override;
+    bool rc_calibration_checks(bool report) override;
     bool pre_arm_checks(bool report) override;
 
 protected: