Correcting the Imam in Recitation When He Makes a Mistake

Is it obligatory for the ma'mum to correct the imam if he makes a mistake in his recitation of the Qur'an?
If the imam makes a mistake in the obligatory recitation, such as his recitation of Surat al-Fatihah, it is obligatory for the ma'mum to correct him.

And if it is in the recommended recitation, we look: If the mistake changes the meaning, it is obligatory for him to object to it; if it does not change the meaning, it is not obligatory.