diff --git a/jupyter/L1-regularization.ipynb b/jupyter/L1-regularization.ipynb
index a58c9c04028a75b44a7b0f3263786a5ea9bed27f..564acbbab72fbf30b78997a24947715e5f81fcf8 100644
--- a/jupyter/L1-regularization.ipynb
+++ b/jupyter/L1-regularization.ipynb
@@ -225,9 +225,9 @@
     "# Draw the contour maps of the data-loss and regularization loss\n",
     "CS = plt.contour(xmesh, ymesh, loss_mesh, 10, cmap=plt.cm.bone)\n",
     "# Draw the L1-balls\n",
-    "CS2 = plt.contour(xmesh, ymesh, l1_mesh, 10, linestyles='dashed', levels=[range(5)]);\n",
+    "CS2 = plt.contour(xmesh, ymesh, l1_mesh, 10, linestyles='dashed', levels=list(range(5)));\n",
     "# Draw the L2-balls\n",
-    "CS3 = plt.contour(xmesh, ymesh, l2_mesh, 10, linestyles='dashed', levels=[range(5)]);\n",
+    "CS3 = plt.contour(xmesh, ymesh, l2_mesh, 10, linestyles='dashed', levels=list(range(5)));\n",
     "\n",
     "# Add green contour lines near the loss minimum\n",
     "CS4 = plt.contour(CS, levels=[0.25, 0.5], colors='g')\n",