diff --git a/activerecord/lib/active_record/migration/join_table.rb b/activerecord/lib/active_record/migration/join_table.rb
index e456c81fc9..e880ae97bb 100644
--- a/activerecord/lib/active_record/migration/join_table.rb
+++ b/activerecord/lib/active_record/migration/join_table.rb
@@ -8,7 +8,7 @@ module ActiveRecord
       end
 
       def join_table_name(table_1, table_2)
-        [table_1, table_2].sort.join("_")
+        [table_1, table_2].sort.join("_").to_sym
       end
     end
   end