Index: wp-content/themes/twentyten/functions.php
===================================================================
--- wp-content/themes/twentyten/functions.php	(revision 23943)
+++ wp-content/themes/twentyten/functions.php	(working copy)
@@ -200,7 +200,7 @@
  */
 function twentyten_admin_header_style() {
 ?>
-<style type="text/css">
+<style type="text/css" id="twentyten-header-css">
 /* Shows the same border as on front end */
 #headimg {
 	border-bottom: 1px solid #000;
Index: wp-content/themes/twentytwelve/inc/custom-header.php
===================================================================
--- wp-content/themes/twentytwelve/inc/custom-header.php	(revision 23943)
+++ wp-content/themes/twentytwelve/inc/custom-header.php	(working copy)
@@ -76,7 +76,7 @@
 
 	// If we get this far, we have custom styles.
 	?>
-	<style type="text/css">
+	<style type="text/css" id="twentytwelve-header-css">
 	<?php
 		// Has the text been hidden?
 		if ( ! display_header_text() ) :
@@ -107,7 +107,7 @@
  */
 function twentytwelve_admin_header_style() {
 ?>
-	<style type="text/css">
+	<style type="text/css" id="twentytwelve-header-css">
 	.appearance_page_custom-header #headimg {
 		border: none;
 		font-family: "Open Sans", ​Helvetica,​ Arial, ​sans-serif;
Index: wp-content/themes/twentyeleven/functions.php
===================================================================
--- wp-content/themes/twentyeleven/functions.php	(revision 23943)
+++ wp-content/themes/twentyeleven/functions.php	(working copy)
@@ -224,7 +224,7 @@
 
 	// If we get this far, we have custom styles. Let's do this.
 	?>
-	<style type="text/css">
+	<style type="text/css" id="twentyeleven-header-css">
 	<?php
 		// Has the text been hidden?
 		if ( 'blank' == $text_color ) :
@@ -259,7 +259,7 @@
  */
 function twentyeleven_admin_header_style() {
 ?>
-	<style type="text/css">
+	<style type="text/css" id="twentyeleven-admin-header-css">
 	.appearance_page_custom-header #headimg {
 		border: none;
 	}
Index: wp-content/themes/twentythirteen/inc/custom-header.php
===================================================================
--- wp-content/themes/twentythirteen/inc/custom-header.php	(revision 23943)
+++ wp-content/themes/twentythirteen/inc/custom-header.php	(working copy)
@@ -80,7 +80,7 @@
 
 	// If we get this far, we have custom styles.
 	?>
-	<style type="text/css">
+	<style type="text/css" id="twentythirteen-header-css">
 	<?php
 		if ( ! empty( $header_image ) ) :
 	?>
@@ -129,7 +129,7 @@
 function twentythirteen_admin_header_style() {
 	$header_image = get_header_image();
 ?>
-	<style type="text/css">
+	<style type="text/css" id="twentythirteen-admin-header-css">
 	.appearance_page_custom-header #headimg {
 		border: none;
 		-webkit-box-sizing: border-box;