diff --git a/libraries/AP_InertialSensor/AP_InertialSensor.cpp b/libraries/AP_InertialSensor/AP_InertialSensor.cpp
index 11212286fb..3a74414444 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor.cpp
+++ b/libraries/AP_InertialSensor/AP_InertialSensor.cpp
@@ -45,7 +45,7 @@ extern const AP_HAL::HAL& hal;
 
 
 
-#if APM_BUILD_COPTER_OR_HELI()
+#if APM_BUILD_COPTER_OR_HELI
 #define DEFAULT_GYRO_FILTER  20
 #define DEFAULT_ACCEL_FILTER 20
 #define DEFAULT_STILL_THRESH 2.5f