diff --git a/tutorial/tutorial_motion.ipynb b/tutorial/tutorial_motion.ipynb
index 2ff3189..f3e3bb5 100644
--- a/tutorial/tutorial_motion.ipynb
+++ b/tutorial/tutorial_motion.ipynb
@@ -653,7 +653,7 @@
         "    self._object_type = []\n",
         "    self._metrics_config = config\n",
         "\n",
-        "  def reset_state():\n",
+        "  def reset_state(self):\n",
         "    self._prediction_trajectory = []\n",
         "    self._prediction_score = []\n",
         "    self._ground_truth_trajectory = []\n",