diff --git a/libraries/AP_Proximity/AP_Proximity_AirSimSITL.h b/libraries/AP_Proximity/AP_Proximity_AirSimSITL.h
index 973bf92dfa..b398417cd4 100644
--- a/libraries/AP_Proximity/AP_Proximity_AirSimSITL.h
+++ b/libraries/AP_Proximity/AP_Proximity_AirSimSITL.h
@@ -40,6 +40,5 @@ public:
 
 private:
     SITL::SITL *sitl;
-    float distance_maximum;
 };
 #endif // CONFIG_HAL_BOARD