Exempted sales where present in gstr 4

Hi

A Composition tax payer has to pay tax at the rate of half per cent of the turnover in the State or Union territory.

Turnover definition as per sec 2(112) - Includes exempt supply 

Hence in  my view Composition tax payer has to pay tax even on his exempt supplies at the rate of 0.5% CGST and 0.5% SGST

Any other views are appreciated

Thank You