common/src/main/java/org/samo_lego/simpleauth/mixin/MixinSlot.java

@@ -16,7 +16,7 @@ public abstract class MixinSlot {
     // Denying item moving etc.
     @Inject(method = "canTakeItems(Lnet/minecraft/entity/player/PlayerEntity;)Z", at = @At(value = "HEAD"), cancellable = true)
     private void canTakeItems(PlayerEntity playerEntity, CallbackInfoReturnable<Boolean> cir) {
-        ServerPlayerEntity player = (ServerPlayerEntity) playerEntity;
+        if (playerEntity instanceof ServerPlayerEntity player) {
             ActionResult result = AuthEventHandler.onTakeItem(player);
 
             if (result == ActionResult.FAIL) {
@@ -32,3 +32,4 @@ public abstract class MixinSlot {
             }
         }
     }
+}