We reverse appellant’s conviction and sentence for possession of cocaine in this case because the trial court failed to instruct the jury that knowledge of the illicit nature of contraband was an essential element of the crime of possession of cocaine. See Chicone v. State, 684 So.2d 736, 745 (Fla. 1996). The matter was properly preserved by a specific request for an instruction. See id. at 745-46. Although the trial court offered a different instruction which was rejected, no instruction on knowledge of the nature of the substance was given. The error was not harmless where knowledge was a contested issue. See id.; Oliver v. State, 707 So.2d 771, 772-3 (Fla. 2d DCA 1998). See also Roberts v. State, 752 So.2d 1230, 1230 (Fla. 1st DCA 2000); Ryals v. State, 716 So.2d 313, 314 (Fla. 4th DCA), rev. denied, 727 So.2d 910 (Fla. 1998).

We affirm appellant’s conviction for carrying a concealed weapon. We have also considered the remaining issues regarding jury instructions which may reoccur in any retrial and find no error in the trial court’s rulings.

Reversed and remanded for a new trial.