diff --git wp-includes/theme.php wp-includes/theme.php
index 4e5f63b..ec4f60e 100644
--- wp-includes/theme.php
+++ wp-includes/theme.php
@@ -1830,22 +1830,30 @@ function wp_update_custom_css_post( $css, $args = array() ) {
  *
  * @param array|string $stylesheet Optional. Stylesheet name or array thereof, relative to theme root.
  * 	                               Defaults to 'editor-style.css'
+ * @param string       $version    Optional. Add version number to stylesheet URL for cache busting.
  */
-function add_editor_style( $stylesheet = 'editor-style.css' ) {
+function add_editor_style( $stylesheet = 'editor-style.css', $version = '' ) {
 	add_theme_support( 'editor-style' );
 
 	if ( ! is_admin() )
 		return;
 
 	global $editor_styles;
+	global $wp_version
+
 	$editor_styles = (array) $editor_styles;
 	$stylesheet    = (array) $stylesheet;
+	$version       = (array) $version;
+
 	if ( is_rtl() ) {
 		$rtl_stylesheet = str_replace('.css', '-rtl.css', $stylesheet[0]);
 		$stylesheet[] = $rtl_stylesheet;
 	}
 
-	$editor_styles = array_merge( $editor_styles, $stylesheet );
+	if ( '' == $version )
+		$version[0] = $wp_version;
+
+	$editor_styles = array_merge( $editor_styles, $stylesheet, $version );
 }
 
 /**