diff --git a/dev/merge_pr.py b/dev/merge_pr.py
index f1ba4c6f701..4af319023d4 100755
--- a/dev/merge_pr.py
+++ b/dev/merge_pr.py
@@ -385,7 +385,7 @@ def choose_jira_assignee(issue, asf_jira):
                 except BaseException:
                     # assume it's a user id, and try to assign (might fail, we just prompt again)
                     assignee = asf_jira.user(raw_assignee)
-                asf_jira.assign_issue(issue.key, assignee.name)
+                assign_issue(asf_jira, issue.key, assignee.name)
                 return assignee
         except KeyboardInterrupt:
             raise
@@ -393,6 +393,19 @@ def choose_jira_assignee(issue, asf_jira):
             traceback.print_exc()
             print("Error assigning JIRA, try again (or leave blank and fix manually)")
 
+def assign_issue(client, issue: int, assignee: str) -> bool:
+    """
+    Assign an issue to a user, which is a shorthand for jira.client.JIRA.assign_issue.
+    The original one has an issue that it will search users again and only choose the assignee
+    from 20 candidates. If it's unmatched, it picks the head blindly. In our case, the assignee
+    is already resolved.
+    """
+    url = getattr(client, "_get_latest_url")(f"issue/{issue}/assignee")
+    payload = {"name": assignee}
+    getattr(client, "_session").put(url, data=json.dumps(payload))
+    return True
+
+
 
 def resolve_jira_issues(title, merge_branches, comment):
     jira_ids = re.findall("CELEBORN-[0-9]{3,6}", title)