function acf_form not working for new posts

I am using this function to output the fields inside a form to create custom post types. There was a bug when calling the function to target a particular post type: 

    acf_form( array( 
            'new_post' => array( 
                    'post_type' => 'my_post_type'
                )
        );

* Fix: undefined index 'new_post' in $defaults
* Fix: passing the post type to the filter to retrieve fields in the case of new posts