diff --git a/libraries/AP_Airspeed/AP_Airspeed_MS4525.cpp b/libraries/AP_Airspeed/AP_Airspeed_MS4525.cpp
index b41d3cbbac..1c837bde29 100644
--- a/libraries/AP_Airspeed/AP_Airspeed_MS4525.cpp
+++ b/libraries/AP_Airspeed/AP_Airspeed_MS4525.cpp
@@ -29,12 +29,6 @@ extern const AP_HAL::HAL &hal;
 
 #define MS4525D0_I2C_ADDR 0x28
 
-#ifdef HAL_AIRSPEED_MS4515DO_I2C_BUS
-#define MS4525D0_I2C_BUS HAL_AIRSPEED_MS4515DO_I2C_BUS
-#else
-#define MS4525D0_I2C_BUS 1
-#endif
-
 AP_Airspeed_MS4525::AP_Airspeed_MS4525(AP_Airspeed &_frontend) :
     AP_Airspeed_Backend(_frontend)
 {