diff --git a/docs/image_summaries.ipynb b/docs/image_summaries.ipynb
index e527860e5a..266729b42c 100644
--- a/docs/image_summaries.ipynb
+++ b/docs/image_summaries.ipynb
@@ -498,14 +498,14 @@
         "  plt.xticks(tick_marks, class_names, rotation=45)\n",
         "  plt.yticks(tick_marks, class_names)\n",
         "\n",
-        "  # Normalize the confusion matrix.\n",
-        "  cm = np.around(cm.astype('float') / cm.sum(axis=1)[:, np.newaxis], decimals=2)\n",
+        "  # Compute the labels from the normalized confusion matrix.\n",
+        "  labels = np.around(cm.astype('float') / cm.sum(axis=1)[:, np.newaxis], decimals=2)\n",
         "\n",
         "  # Use white text if squares are dark; otherwise black.\n",
         "  threshold = cm.max() / 2.\n",
         "  for i, j in itertools.product(range(cm.shape[0]), range(cm.shape[1])):\n",
         "    color = \"white\" if cm[i, j] > threshold else \"black\"\n",
-        "    plt.text(j, i, cm[i, j], horizontalalignment=\"center\", color=color)\n",
+        "    plt.text(j, i, labels[i, j], horizontalalignment=\"center\", color=color)\n",
         "\n",
         "  plt.tight_layout()\n",
         "  plt.ylabel('True label')\n",