Petitioner, pro se, seeks a writ of mandamus which we treat as a petition for writ of certiorari and grant. ' The trial court modified petitioner’s sentence by vacating a monetary assessment and imposing fifty hours of community service at the termination of his incarceration in lieu of that assessment. The fifty hours of community service represent an increase in petitioner’s sentence and an increase of a lawful sentence is prohibited. Troupe v. Rowe, 283 So.2d 857 (Fla. 1973); Cherry v. State, 439 So.2d 998 (Fla. 4th DCA 1983). This matter is remanded to the trial court for further proceedings consistent with this opinion.

CERTIORARI GRANTED.