diff --git a/python/tutorial.ipynb b/python/tutorial.ipynb
index c0933859..fcfd8b74 100644
--- a/python/tutorial.ipynb
+++ b/python/tutorial.ipynb
@@ -1360,7 +1360,7 @@
     "lines = ax[0,0].plot(sim_time, force)\n",
     "ax[0,0].set_title('contact force')\n",
     "ax[0,0].set_ylabel('Newton')\n",
-    "ax[0,0].legend(lines, ('normal z', 'friction x', 'friction y'));\n",
+    "ax[0,0].legend(list(lines), ('normal z', 'friction x', 'friction y'));\n",
     "\n",
     "ax[1,0].plot(sim_time, acceleration)\n",
     "ax[1,0].set_title('acceleration')\n",