diff --git a/conf/templates/pyproject.toml b/conf/templates/pyproject.toml
index daf2d4e4..41163950 100644
--- a/conf/templates/pyproject.toml
+++ b/conf/templates/pyproject.toml
@@ -5,6 +5,7 @@
   enable_error_code = [
     "explicit-override",
     "ignore-without-code",
+    "possibly-undefined",
   ]
 
 [tool.isort]