Include for only posts with category isn't working

Hi,

I seem to be having trouble with including metaboxes on a specific category only. I want to be able to show the metabox on posts with the category ID of 94. But it just shows up on all posts. Code is below. Am I doing something wrong?

// Events Posts –  /////////////////
$meta_boxes[] = array(
	// Meta box id, UNIQUE per meta box. Optional since 4.1.5
	'id' => 'current_event_id',
	// Meta box title - Will appear at the drag and drop handle bar. Required.
	'title' => __( 'Current Event Extra content', 'rwmb' ),
	// Post types, accept custom post types as well - DEFAULT is array('post'). Optional.
	'pages' => array( 'post' ),
	// Where the meta box appear: normal (default), advanced, side. Optional.
	'context' => 'normal',
	// Order of meta box: high (default), low. Optional.
	'priority' => 'high',
	// Auto save: true, false (default). Optional.
	'autosave' => true,
	// Register this meta box for posts matched below conditions
	'include' => array(
		'category'  => array( 94 )
		),
	// List of meta fields
	'fields' => array(
	// TEXT
		array(
			// Field name - Will be used as label
			'name'  => __( 'Ribbon Text', 'meta-box' ),
			// Field ID, i.e. the meta key
			'id'    => "{$prefix}event-ribbon-text",
			// Field description (optional)
			'desc'  => __( 'Enter text for the ribbon e.g Date of event', 'meta-box' ),
			'type'  => 'text',
		),
	),

);