diff --git a/frontend/src/components/molecules/messages/components/Avatar.tsx b/frontend/src/components/molecules/messages/components/Avatar.tsx
index cfaf3221e7..a241a0480b 100644
--- a/frontend/src/components/molecules/messages/components/Avatar.tsx
+++ b/frontend/src/components/molecules/messages/components/Avatar.tsx
@@ -14,7 +14,7 @@ interface Props {
   hide?: boolean;
 }
 
-const getAuthorAvatarId = (author) => {
+const getAuthorAvatarId = (author: string | undefined) => {
   if (!author) return 'default';
 
   return author