diff --git a/upgrade_migrations/version_1_1_2.rb b/upgrade_migrations/version_1_1_2.rb
index 1157327..a4ef8e9 100644
--- a/upgrade_migrations/version_1_1_2.rb
+++ b/upgrade_migrations/version_1_1_2.rb
@@ -4,6 +4,6 @@ class Version04UpdateImpressionsTable < ActiveRecord::Migration
   end
 
   def self.down
-    remove_column :impressions, :impressionable_type_message_index
+    remove_index :impressions, :impressionable_type_message_index
   end
 end