diff --git a/gtsam/geometry/doc/Rot2.ipynb b/gtsam/geometry/doc/Rot2.ipynb
index 704915b4c..610727090 100644
--- a/gtsam/geometry/doc/Rot2.ipynb
+++ b/gtsam/geometry/doc/Rot2.ipynb
@@ -67,7 +67,7 @@
     {
       "cell_type": "markdown",
       "source": [
-        "# Initialization and properties"
+        "## Initialization and properties"
       ],
       "metadata": {
         "id": "gZRXZTrJ7mqJ"