diff --git a/notebooks/wp3/bias_assessment.ipynb b/notebooks/wp3/bias_assessment.ipynb
index a22e362..81324f7 100644
--- a/notebooks/wp3/bias_assessment.ipynb
+++ b/notebooks/wp3/bias_assessment.ipynb
@@ -62,6 +62,16 @@
     "    \"ukmo\": {\"system\": \"601\"},\n",
     "}\n",
     "assert all(\"system\" in v for v in centres.values())\n",
+    "assert set(cetres) <= {\n",
+    "    \"cmcc\",\n",
+    "    \"dwd\",\n",
+    "    \"eccc\",\n",
+    "    \"ecmwf\",\n",
+    "    \"jma\",\n",
+    "    \"meteo_france\",\n",
+    "    \"ncep\",\n",
+    "    \"ukmo\",\n",
+    "}\n",
     "\n",
     "# Regions\n",
     "regions = {\n",