diff --git a/ui/src/shared/components/PersistentLegend.js b/ui/src/shared/components/PersistentLegend.js
index fbae383a0e..2a6f28917c 100644
--- a/ui/src/shared/components/PersistentLegend.js
+++ b/ui/src/shared/components/PersistentLegend.js
@@ -35,7 +35,7 @@ class PersistentLegend extends Component {
   }
 }
 
-const {func} = PropTypes
+const {func, shape} = PropTypes
 
 PersistentLegend.propTypes = {dygraph: shape({})}