diff --git a/openmm_septop/septop_tutorial.ipynb b/openmm_septop/septop_tutorial.ipynb
index 5fa0dbc..da81f4a 100644
--- a/openmm_septop/septop_tutorial.ipynb
+++ b/openmm_septop/septop_tutorial.ipynb
@@ -23,7 +23,7 @@
    "id": "23881797-0bd3-408b-9212-ac206d46cd39",
    "metadata": {},
    "source": [
-    "<img src=\"septop_cycle.png\" width=600/>"
+    "<img src=\"septop_cycle.png\" width=\"600\">"
    ]
   },
   {