diff --git a/pagure/ui/issues.py b/pagure/ui/issues.py
index 2a12cb4..e91573d 100644
--- a/pagure/ui/issues.py
+++ b/pagure/ui/issues.py
@@ -241,16 +241,17 @@ def update_issue(repo, issueid, username=None, namespace=None):
             # other fields will be missing for non-admin and thus reset if we let them
             if repo_admin:
                 # Assign or update assignee of the ticket
-                message = pagure.lib.add_issue_assignee(
-                    SESSION,
-                    issue=issue,
-                    assignee=assignee or None,
-                    user=flask.g.fas_user.username,
-                    ticketfolder=APP.config['TICKETS_FOLDER'],
-                )
-                SESSION.commit()
-                if message:
-                    messages.add(message)
+                if assignee:
+                    message = pagure.lib.add_issue_assignee(
+                        SESSION,
+                        issue=issue,
+                        assignee=assignee or None,
+                        user=flask.g.fas_user.username,
+                        ticketfolder=APP.config['TICKETS_FOLDER'],
+                    )
+                    SESSION.commit()
+                    if message:
+                        messages.add(message)
 
                 # Update priority
                 if str(new_priority) in repo.priorities: