Primary key cannot be defined upon persistent virtual column

ERROR 1903 (HY000): Primary key cannot be defined upon a computed column .

Virtual column was a nice way to remove stuff like
PRIMARY KEY (`COD_INV`, `COD_FAM`, `COD_MAG`, `COD_FIL`, `COD_ID_INV`)

• It's a bad practice to use triggers
• It's a bad practice to use hidden primary key ,
• It's a bad practice to use virtual column .

What could we advice that can be transparent to the application layer to fixe such bad design for InnoDB.

Rewrite the application is not always a political correct answer.