diff --git a/examples/introduction.ipynb b/examples/introduction.ipynb
index ec7468091..a0720fdc9 100644
--- a/examples/introduction.ipynb
+++ b/examples/introduction.ipynb
@@ -1224,7 +1224,8 @@
     "graph = graph_builder.compile(checkpointer=memory)\n",
     "```\n",
     "</pre>\n",
-    "</pre>details"
+    "</pre>\n",
+    "</details>"
    ]
   },
   {