diff --git a/analysis/demand-metric.ipynb b/analysis/demand-metric.ipynb
index 78afd0f3a2091d09c1a23f698827e2ed6e5cca23..525bde211afcabeecf52f1e88f3c91c02a77a152 100644
--- a/analysis/demand-metric.ipynb
+++ b/analysis/demand-metric.ipynb
@@ -86,6 +86,8 @@
    "metadata": {},
    "outputs": [],
    "source": [
+    "import os\n",
+    "\n",
     "demand.to_csv(os.path.join(results_dir, f'exp{exp_id}_demand.csv'), index=False)"
    ]
   }