diff --git a/ts/routes/reviewer/reviewer.ts b/ts/routes/reviewer/reviewer.ts
index da18758db..8601f5951 100644
--- a/ts/routes/reviewer/reviewer.ts
+++ b/ts/routes/reviewer/reviewer.ts
@@ -224,10 +224,10 @@ export class ReviewerState {
             const noteIds = [this.currentCard.card.noteId];
             if (this._cardData.marked) {
                 await removeNoteTags({ noteIds, tags: "marked" });
-                this.undoStatus!.undo = tr.actionsRemoveTag();
+                this.setUndo(tr.actionsRemoveTag());
             } else {
                 await addNoteTags({ noteIds, tags: "marked" });
-                this.undoStatus!.undo = tr.actionsUpdateTag();
+                this.setUndo(tr.actionsUpdateTag());
             }
             this.marked.update($marked => !$marked);
             this._cardData.marked = !this._cardData.marked;