             add: isAdd
         )
         reactionMutation = result.viewModel
-        cell.perform(operation: result.operation, content: content)
+
+        cell?.perform(operation: result.operation, content: content)
+
         update(animated: true)
         generator.impactOccurred()
         client.react(subjectID: object.id, content: content, isAdd: isAdd) { [weak self] result in

    // MARK: DoubleTappableCellDelegate
    
    func didDoubleTap(cell: DoubleTappableCell) {
        guard let reactionCell = collectionContext?.cellForItem(at: numberOfItems() - 1, sectionController: self) as? IssueCommentReactionCell else {
            return
        }
        
        let reaction = ReactionContent.thumbsUp
        guard let reactions = reactionMutation ?? self.object?.reactions,
            !reactions.viewerDidReact(reaction: reaction)
            else { return }
        
        react(cell: reactionCell, content: reaction, isAdd: true)
    }

    // MARK: IssueCommentDetailCellDelegate

        return true
    }

    private func react(cell: IssueCommentReactionCell?, content: ReactionContent, isAdd: Bool) {
        guard let object = self.object else { return }

        let previousReaction = reactionMutation
