alter table drop foreign key ERROR 1064 (42000)

Question

mysql> alter table orders_testorder drop foreign key 'orders_testorder_confirmed_icdo_dx_id_33d3fe14_fk_orders_ic';

ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ''orders_testorder_confirmed_icdo_dx_id_33d3fe14_fk_orders_ic'' at line 1

The name is correct. This is standard syntax.

Why does this not work?