JavaFX KeyEvent returns KeyCode.UNDEFINED

I created a simple JavaFX application that receives input from the user in a TextField. I attached the KeyTyped event from SceneBuilder to the controller. My function looks like this:

@FXML private void keyTyped(KeyEvent event) {
    System.out.println(event.getCode().equals(KeyCode.ENTER));
}

This function always prints out UNDEFINED when I type the enter key. Any ideas on how to fix this? Other letters I type seem to have the same problem as well.