diff --git a/09_tabular.ipynb b/09_tabular.ipynb
index b767040..5cb8d51 100644
--- a/09_tabular.ipynb
+++ b/09_tabular.ipynb
@@ -726,6 +726,13 @@
    "metadata": {},
    "outputs": [],
    "source": [
+    "# Errata:\n",
+    "#   This line should have been:\n",
+    "#     cond = ((df.saleYear<2011) | ((df.saleYear==2011) & (df.saleMonth<10))\n",
+    "#\n",
+    "#   Correcting this line is postponed to a future edition of the book because\n",
+    "#   it requires a re-analysis of the data. For discussion see:\n",
+    "#   https://github.com/fastai/fastbook/issues/325.\n",
     "cond = (df.saleYear<2011) | (df.saleMonth<10)\n",
     "train_idx = np.where( cond)[0]\n",
     "valid_idx = np.where(~cond)[0]\n",