wp.customize is undefined in customizer scripts

I have some scripts I am loading in the customizer like this:

add_action('customize_controls_enqueue_scripts', function() {
    wp_enqueue_script('jquery');
    wp_enqueue_script('json-editor', 'https://cdnjs.cloudflare.com/ajax/libs/jsoneditor/9.0.5/jsoneditor.min.js');
    wp_enqueue_style('json-editor', 'https://cdnjs.cloudflare.com/ajax/libs/jsoneditor/9.0.5/jsoneditor.min.css');
    wp_enqueue_script('wf-customizer', get_template_directory_uri() . '/assets/js/customizer.js');
    wp_localize_script('wf-customizer', 'conditions', $this->conditions);
});

In the wf-customizer script, I am trying to use this:

wp.customize.bind('ready', function() {
    //...
});

But I keep getting Cannot read property 'bind' of undefined in the JS console. Somehow, wp.customize is undefined for me.