diff --git a/selfdrive/locationd/locationd.py b/selfdrive/locationd/locationd.py
index 4cde1e5ad4..7f5541b8c2 100755
--- a/selfdrive/locationd/locationd.py
+++ b/selfdrive/locationd/locationd.py
@@ -49,7 +49,7 @@ class LocationEstimator:
 
     self.debug = debug
 
-    self.posenet_stds = [POSENET_STD_INITIAL_VALUE] * (POSENET_STD_HIST_HALF * 2)
+    self.posenet_stds = np.array([POSENET_STD_INITIAL_VALUE] * (POSENET_STD_HIST_HALF * 2))
     self.car_speed = 0.0
     self.camodo_yawrate_distribution = np.array([0.0, 10.0])  # mean, std
     self.device_from_calib = np.eye(3)
@@ -168,8 +168,8 @@ class LocationEstimator:
       if np.linalg.norm(rot_calib_std) > 10 * ROTATION_SANITY_CHECK or np.linalg.norm(trans_calib_std) > 10 * TRANS_SANITY_CHECK:
         return HandleLogResult.INPUT_INVALID
 
-      self.posenet_stds.pop(0)
-      self.posenet_stds.append(trans_calib_std[0])
+      self.posenet_stds = np.roll(self.posenet_stds, -1)
+      self.posenet_stds[-1] = trans_calib_std[0]
 
       # Multiply by N to avoid to high certainty in kalman filter because of temporally correlated noise
       rot_calib_std *= 10