diff --git a/web/src/components/Memo.tsx b/web/src/components/Memo.tsx
index 64fecbda..d6c0e2c8 100644
--- a/web/src/components/Memo.tsx
+++ b/web/src/components/Memo.tsx
@@ -39,7 +39,7 @@ const Memo: React.FC<Props> = (props: Props) => {
   const isVisitorMode = userService.isVisitorMode();
 
   useEffect(() => {
-    let intervalFlag = -1;
+    let intervalFlag: any = -1;
     if (Date.now() - memo.createdTs < 1000 * 60 * 60 * 24) {
       intervalFlag = setInterval(() => {
         setCreatedAtStr(getFormatedMemoCreatedAtStr(memo.createdTs, i18n.language));