MILLS, Judge.
Fredricks contends the trial court erred in retaining jurisdiction for the first half of four sentences pursuant to Section 947.16(3), Florida Statutes (Supp. 1982). The crimes were committed on 5 March 1982, and the statute as amended took effect on 20 April 1982. Chapter 82-171, Section 19, Laws of Florida. Nevertheless, we affirm because the issue was not raised below.
Ex post facto application of the retention statute is not fundamental error and objection must be made at the trial level to preserve the issue for appellate review. Williams v. State, 414 So.2d 509 (Fla. 1982); Brown v. State, 428 So.2d 369 (Fla. 5th DCA 1983).
AFFIRMED.
SHIVERS and ZEHMER, JJ., concur.