diff --git a/wp-admin/includes/template.php b/wp-admin/includes/template.php
index 28d8b03e3b..6003f5fd0c 100644
--- a/wp-admin/includes/template.php
+++ b/wp-admin/includes/template.php
@@ -70,19 +70,28 @@ class Walker_Category_Checklist extends Walker {
 	 * @param int    $id       ID of the current term.
 	 */
 	function start_el( &$output, $category, $depth = 0, $args = array(), $id = 0 ) {
-		extract($args);
-		if ( empty($taxonomy) )
+		if ( empty( $args['taxonomy'] ) ) {
 			$taxonomy = 'category';
+		} else {
+			$taxonomy = $args['taxonomy'];
+		}
 
-		if ( $taxonomy == 'category' )
+		if ( $taxonomy == 'category' ) {
 			$name = 'post_category';
-		else
-			$name = 'tax_input['.$taxonomy.']';
+		} else {
+			$name = 'tax_input[' . $taxonomy . ']';
+		}
+		$args['popular_cats'] = empty( $args['popular_cats'] ) ? array() : $args['popular_cats'];
+		$class = in_array( $category->term_id, $args['popular_cats'] ) ? ' class="popular-category"' : '';
 
-		$class = in_array( $category->term_id, $popular_cats ) ? ' class="popular-category"' : '';
+		$args['selected_cats'] = empty( $args['selected_cats'] ) ? array() : $args['selected_cats'];
 
 		/** This filter is documented in wp-includes/category-template.php */
-		$output .= "\n<li id='{$taxonomy}-{$category->term_id}'$class>" . '<label class="selectit"><input value="' . $category->term_id . '" type="checkbox" name="'.$name.'[]" id="in-'.$taxonomy.'-' . $category->term_id . '"' . checked( in_array( $category->term_id, $selected_cats ), true, false ) . disabled( empty( $args['disabled'] ), false, false ) . ' /> ' . esc_html( apply_filters( 'the_category', $category->name ) ) . '</label>';
+		$output .= "\n<li id='{$taxonomy}-{$category->term_id}'$class>" .
+			'<label class="selectit"><input value="' . $category->term_id . '" type="checkbox" name="'.$name.'[]" id="in-'.$taxonomy.'-' . $category->term_id . '"' .
+			checked( in_array( $category->term_id, $args['selected_cats'] ), true, false ) .
+			disabled( empty( $args['disabled'] ), false, false ) . ' /> ' .
+			esc_html( apply_filters( 'the_category', $category->name ) ) . '</label>';
 	}
 
 	/**