diff --git a/docs/notebooks/examples/ex_committor.ipynb b/docs/notebooks/examples/ex_committor.ipynb
index e09bc262..1cf8411c 100644
--- a/docs/notebooks/examples/ex_committor.ipynb
+++ b/docs/notebooks/examples/ex_committor.ipynb
@@ -63,7 +63,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "# Initialize committor model and training variables"
+    "## Initialize committor model and training variables"
    ]
   },
   {
@@ -104,10 +104,11 @@
    ]
   },
   {
+   "attachments": {},
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "# Load data"
+    "## Load data"
    ]
   },
   {
@@ -178,7 +179,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "# Initialize trainer and fit model"
+    "## Initialize trainer and fit model"
    ]
   },
   {
@@ -263,10 +264,11 @@
    ]
   },
   {
+   "attachments": {},
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "# Visualize results"
+    "## Visualize results"
    ]
   },
   {
@@ -299,7 +301,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "# Export model with tracing"
+    "## Export model with tracing"
    ]
   },
   {
@@ -316,7 +318,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "# OPTIONAL: Apply preprocessing to compute descriptors \n",
+    "## OPTIONAL: Apply preprocessing to compute descriptors \n",
     "You can add preprocessing module to the model by `model.preprocessing = Module`\n",
     "Here we just create a mock preprocessing that swaps `p.x` and `p.y` "
    ]