diff --git a/app/models/topic.py b/app/models/topic.py
index a4774d6..dbf3bce 100644
--- a/app/models/topic.py
+++ b/app/models/topic.py
@@ -54,7 +54,8 @@ class Topic(Post):
 
     def delete(self):
         """Recursively delete topic and all associated contents."""
-        self.thread.delete()
+        if self.promotion is None:
+            self.thread.delete()
         db.session.delete(self)
 
     def __repr__(self):