diff --git a/db/migrate/20110211021925_fix_target_on_notification.rb b/db/migrate/20110211021925_fix_target_on_notification.rb
new file mode 100644
index 000000000..2ae9412e3
--- /dev/null
+++ b/db/migrate/20110211021925_fix_target_on_notification.rb
@@ -0,0 +1,26 @@
+class FixTargetOnNotification < ActiveRecord::Migration
+  def self.up
+    execute("UPDATE notifications " +
+"SET target_type='Post' " + 
+"WHERE action = 'comment_on_post' OR action = 'also_commented'")
+
+    execute("UPDATE notifications " +
+"SET target_type='Request' " + 
+"WHERE action = 'new_request' OR action = 'request_accepted'")
+
+    execute("UPDATE notifications " +
+"SET target_type='Mention' " + 
+"WHERE action = 'mentioned'")
+
+    execute("create temporary table t1 "+
+    "(select notifications.id as n_id " +
+    "from notifications LEFT JOIN mentions "+
+    "ON notifications.target_id = mentions.id  "+
+    "WHERE notifications.action = 'mentioned' AND mentions.id IS NULL)")
+    
+    execute("DELETE notifications.* FROM notifications, t1 WHERE notifications.id = t1.n_id")
+  end
+
+  def self.down
+  end
+end