diff --git a/src/ui/components/ModalOverlay.tsx b/src/ui/components/ModalOverlay.tsx
index a1747a201..eb6357728 100644
--- a/src/ui/components/ModalOverlay.tsx
+++ b/src/ui/components/ModalOverlay.tsx
@@ -26,7 +26,7 @@ export default class ModalOverlay extends Component<{
   onClose: () => void;
   children?: React.ReactNode;
 }> {
-  ref: HTMLElement;
+  ref: HTMLElement | null | undefined;
 
   setRef = (ref: HTMLElement) => {
     this.ref = ref;