diff --git wp-includes/class-wp-customize-setting.php wp-includes/class-wp-customize-setting.php
index 0207b70..3592c62 100644
--- wp-includes/class-wp-customize-setting.php
+++ wp-includes/class-wp-customize-setting.php
@@ -170,8 +170,10 @@ class WP_Customize_Setting {
 	 *
 	 * @return false|null False if cap check fails or value isn't set.
 	 */
-	public final function save() {
-		$value = $this->post_value();
+	public final function save( $value = null ) {
+		if ( ! isset( $value ) ) {
+			$value = $this->post_value();
+		}
 
 		if ( ! $this->check_capabilities() || ! isset( $value ) )
 			return false;