diff --git a/dmi.py b/dmi.py
index 32bbe7c..34d6d27 100644
--- a/dmi.py
+++ b/dmi.py
@@ -55,7 +55,7 @@ def main():
 
                         if stabilizer.locked():
                             position = position_tracker.input(samples_ref, samples_meas)
-                            position_acc += np.sum(position)/len(position)
+                            position_acc += np.mean(position)
                             if throttle == 0:
                                 gui.update_position(position_acc/throttle_factor)
                                 position_acc = 0.0