diff --git a/src/modules/position_estimator_inav/inertial_filter.h b/src/modules/position_estimator_inav/inertial_filter.h
index cdeb4cfc6c..15ac93d874 100644
--- a/src/modules/position_estimator_inav/inertial_filter.h
+++ b/src/modules/position_estimator_inav/inertial_filter.h
@@ -8,6 +8,6 @@
 #include <stdbool.h>
 #include <drivers/drv_hrt.h>
 
-void inertial_filter_predict(float dt, float x[3], float acc);
+void inertial_filter_predict(float dt, float x[2], float acc);
 
-void inertial_filter_correct(float e, float dt, float x[3], int i, float w);
+void inertial_filter_correct(float e, float dt, float x[2], int i, float w);