diff --git a/script/import_scripts/base.rb b/script/import_scripts/base.rb
index cf6eaeeb62f..b938f9ef113 100644
--- a/script/import_scripts/base.rb
+++ b/script/import_scripts/base.rb
@@ -470,7 +470,7 @@ class ImportScripts::Base
 
   def update_bumped_at
     puts "", "updating bumped_at on topics"
-    Post.exec_sql("update topics t set bumped_at = (select max(created_at) from posts where topic_id = t.id and post_type != #{Post.types[:moderator_action]})")
+    Post.exec_sql("update topics t set bumped_at = COALESCE((select max(created_at) from posts where topic_id = t.id and post_type != #{Post.types[:moderator_action]}), bumped_at)")
   end
 
   def update_last_posted_at