diff --git a/api/services/workflow_comment_service.py b/api/services/workflow_comment_service.py
index ac20a87c31..ec979a79f0 100644
--- a/api/services/workflow_comment_service.py
+++ b/api/services/workflow_comment_service.py
@@ -65,12 +65,16 @@ class WorkflowCommentService:
 
         # Cache accounts on objects
         for comment in comments:
-            comment._created_by_account_cache = account_map.get(comment.created_by)
-            comment._resolved_by_account_cache = account_map.get(comment.resolved_by) if comment.resolved_by else None
+            setattr(comment, "_created_by_account_cache", account_map.get(comment.created_by))
+            setattr(
+                comment,
+                "_resolved_by_account_cache",
+                account_map.get(comment.resolved_by) if comment.resolved_by else None,
+            )
             for reply in comment.replies:
-                reply._created_by_account_cache = account_map.get(reply.created_by)
+                setattr(reply, "_created_by_account_cache", account_map.get(reply.created_by))
             for mention in comment.mentions:
-                mention._mentioned_user_account_cache = account_map.get(mention.mentioned_user_id)
+                setattr(mention, "_mentioned_user_account_cache", account_map.get(mention.mentioned_user_id))
 
     @staticmethod
     def get_comment(tenant_id: str, app_id: str, comment_id: str, session: Session | None = None) -> WorkflowComment: