1 files changed, 4 insertions, 0 deletions
diff --git a/activerecord/lib/rails/generators/active_record/model/templates/migration.rb b/activerecord/lib/rails/generators/active_record/model/templates/migration.rb
index 70e064be21..7d4e1a7404 100644
--- a/activerecord/lib/rails/generators/active_record/model/templates/migration.rb
+++ b/activerecord/lib/rails/generators/active_record/model/templates/migration.rb
@@ -8,6 +8,10 @@ class <%= migration_class_name %> < ActiveRecord::Migration
       t.timestamps
 <% end -%>
     end
+
+<% attributes.select {|attr| attr.reference? }.each do |attribute| -%>
+    add_index :<%= table_name %>, :<%= attribute.name %>_id
+<% end -%>
   end
 
   def down