diff --git a/types/react-window/tslint.json b/types/react-window/tslint.json
index 3db14f85ea..5b394cbcc8 100644
--- a/types/react-window/tslint.json
+++ b/types/react-window/tslint.json
@@ -1 +1,6 @@
-{ "extends": "dtslint/dt.json" }
+{
+    "extends": "dtslint/dt.json",
+    "rules": {
+        "no-null-undefined-union": false // needed for optional Refs
+    }
+}