endless loop in Leonardo

Hi to all I have this problem with Leonardo. Code works fine on uno.

void setup(){

Serial.begin(9600); while(!Serial){ } }

This is a simple code but my Leonardo stay inside the while(!Serial) loop. I even added Serial.begin after while loop but still. It never go to void loop()

try change to : !Serial*()*

For fun I did that but I gave me a error.
I removed the while loop and then nothing happens.
Is there no one with arduino Leonardo that can help