diff --git a/pagure/lib/model.py b/pagure/lib/model.py
index 2cc413c..fc2a2a8 100644
--- a/pagure/lib/model.py
+++ b/pagure/lib/model.py
@@ -527,7 +527,10 @@ class IssueComment(BASE):
 
     issue = relation(
         'Issue', foreign_keys=[issue_uid], remote_side=[Issue.uid],
-        backref=backref('comments', order_by="IssueComment.date_created")
+        backref=backref(
+            'comments', cascade="delete, delete-orphan",
+            order_by="IssueComment.date_created"
+        ),
     )
     user = relation('User', foreign_keys=[user_id],
                     remote_side=[User.id], backref='comment_issues')
@@ -781,7 +784,10 @@ class PullRequestComment(BASE):
                         'pull_request_comments',
                         order_by="PullRequestComment.date_created"))
     pull_request = relation(
-        'PullRequest', backref='comments',
+        'PullRequest',
+        backref=backref(
+            'comments', cascade="delete, delete-orphan",
+        ),
         foreign_keys=[pull_request_uid],
         remote_side=[PullRequest.uid])
 
diff --git a/pagure/ui/repo.py b/pagure/ui/repo.py
index 170b67e..2310130 100644
--- a/pagure/ui/repo.py
+++ b/pagure/ui/repo.py
@@ -700,8 +700,6 @@ def delete_repo(repo, username=None):
                 SESSION.delete(comment)
             SESSION.commit()
             SESSION.delete(issue)
-        for preq in repo.requests:
-            SESSION.delete(preq)
         SESSION.delete(repo)
         SESSION.commit()
     except SQLAlchemyError, err:  # pragma: no cover