1 files changed, 6 insertions, 2 deletions
diff --git a/db/migrate/20170210103609_add_index_to_user_agent_detail.rb b/db/migrate/20170210103609_add_index_to_user_agent_detail.rb
index c01753cfbd2..2d8329b7862 100644
--- a/db/migrate/20170210103609_add_index_to_user_agent_detail.rb
+++ b/db/migrate/20170210103609_add_index_to_user_agent_detail.rb
@@ -8,7 +8,11 @@ class AddIndexToUserAgentDetail < ActiveRecord::Migration
 
   disable_ddl_transaction!
 
-  def change
-    add_concurrent_index(:user_agent_details, [:subject_id, :subject_type])
+  def up
+    add_concurrent_index :user_agent_details, [:subject_id, :subject_type]
+  end
+
+  def down
+    remove_index :user_agent_details, [:subject_id, :subject_type] if index_exists? :user_agent_details, [:subject_id, :subject_type]
   end
 end