diff --git a/ArduCopter/rate_thread.cpp b/ArduCopter/rate_thread.cpp
index 5b64301fb7bec9..d0b09d438d0393 100644
--- a/ArduCopter/rate_thread.cpp
+++ b/ArduCopter/rate_thread.cpp
@@ -407,10 +407,12 @@ void Copter::rate_controller_thread()
 */
 void Copter::rate_controller_filter_update()
 {
+#if AP_INERTIALSENSOR_HARMONICNOTCH_ENABLED
     // update the frontend center frequencies of notch filters
     for (auto &notch : ins.harmonic_notches) {
         update_dynamic_notch(notch);
     }
+#endif  // AP_INERTIALSENSOR_HARMONICNOTCH_ENABLED
 
     // this copies backend data to the frontend and updates the notches
     ins.update_backend_filters();