diff --git a/sw/airborne/subsystems/ahrs/ahrs_int_cmpl.h b/sw/airborne/subsystems/ahrs/ahrs_int_cmpl.h
index ab0a7d939d..4671621d26 100644
--- a/sw/airborne/subsystems/ahrs/ahrs_int_cmpl.h
+++ b/sw/airborne/subsystems/ahrs/ahrs_int_cmpl.h
@@ -41,11 +41,12 @@ struct AhrsIntCmpl {
 extern struct AhrsIntCmpl ahrs_impl;
 
 
+#ifdef AHRS_UPDATE_FW_ESTIMATOR
 // TODO copy ahrs to state instead of estimator
 void ahrs_update_fw_estimator(void);
 extern float ins_roll_neutral;
 extern float ins_pitch_neutral;
-
+#endif
 
 
 #endif /* AHRS_INT_CMPL_H */