diff --git a/ui/redux/reducers/comments.js b/ui/redux/reducers/comments.js
index 5ddb7d310..cc9553f54 100644
--- a/ui/redux/reducers/comments.js
+++ b/ui/redux/reducers/comments.js
@@ -26,7 +26,7 @@ export default handleActions(
       const { comment, claimId }: { comment: Comment, claimId: string } = action.data;
       const commentById = Object.assign({}, state.commentById);
       const byId = Object.assign({}, state.byId);
-      const comments = byId[claimId];
+      const comments = byId[claimId] || [];
       const newCommentIds = comments.slice();
 
       // add the comment by its ID