diff --git a/wp-admin/admin-header.php b/wp-admin/admin-header.php
index 2f26cf3fa..1494b298c 100644
--- a/wp-admin/admin-header.php
+++ b/wp-admin/admin-header.php
@@ -55,7 +55,7 @@ var userSettings = {
 		'uid': '<?php if ( ! isset($current_user) ) $current_user = wp_get_current_user(); echo $current_user->ID; ?>',
 		'time':'<?php echo time() ?>'
 	},
-	ajaxurl = '<?php echo admin_url('admin-ajax.php'); ?>',
+	ajaxurl = '<?php echo admin_url( 'admin-ajax.php', 'relative' ); ?>',
 	pagenow = '<?php echo $current_screen->id; ?>',
 	typenow = '<?php echo $current_screen->post_type; ?>',
 	adminpage = '<?php echo $admin_body_class; ?>',
diff --git a/wp-admin/includes/image-edit.php b/wp-admin/includes/image-edit.php
index daf6221b7..0d4605489 100644
--- a/wp-admin/includes/image-edit.php
+++ b/wp-admin/includes/image-edit.php
@@ -67,7 +67,7 @@ function wp_image_editor($post_id, $msg = false) {
 	<input type="hidden" id="imgedit-y-<?php echo $post_id; ?>" value="<?php echo $meta['height']; ?>" />
 
 	<div id="imgedit-crop-<?php echo $post_id; ?>" class="imgedit-crop-wrap">
-	<img id="image-preview-<?php echo $post_id; ?>" onload="imageEdit.imgLoaded('<?php echo $post_id; ?>')" src="<?php echo admin_url('admin-ajax.php'); ?>?action=imgedit-preview&amp;_ajax_nonce=<?php echo $nonce; ?>&amp;postid=<?php echo $post_id; ?>&amp;rand=<?php echo rand(1, 99999); ?>" />
+	<img id="image-preview-<?php echo $post_id; ?>" onload="imageEdit.imgLoaded('<?php echo $post_id; ?>')" src="<?php echo admin_url( 'admin-ajax.php', 'relative' ); ?>?action=imgedit-preview&amp;_ajax_nonce=<?php echo $nonce; ?>&amp;postid=<?php echo $post_id; ?>&amp;rand=<?php echo rand(1, 99999); ?>" />
 	</div>
 
 	<div class="imgedit-submit">
diff --git a/wp-admin/includes/media.php b/wp-admin/includes/media.php
index 12f4d3f1d..f77459a7e 100644
--- a/wp-admin/includes/media.php
+++ b/wp-admin/includes/media.php
@@ -334,7 +334,7 @@ wp_enqueue_style( 'ie' );
 //<![CDATA[
 addLoadEvent = function(func){if(typeof jQuery!="undefined")jQuery(document).ready(func);else if(typeof wpOnload!='function'){wpOnload=func;}else{var oldonload=wpOnload;wpOnload=function(){oldonload();func();}}};
 var userSettings = {'url':'<?php echo SITECOOKIEPATH; ?>','uid':'<?php if ( ! isset($current_user) ) $current_user = wp_get_current_user(); echo $current_user->ID; ?>','time':'<?php echo time(); ?>'};
-var ajaxurl = '<?php echo admin_url('admin-ajax.php'); ?>', pagenow = 'media-upload-popup', adminpage = 'media-upload-popup',
+var ajaxurl = '<?php echo admin_url( 'admin-ajax.php', 'relative' ); ?>', pagenow = 'media-upload-popup', adminpage = 'media-upload-popup',
 isRtl = <?php echo (int) is_rtl(); ?>;
 //]]>
 </script>
diff --git a/wp-admin/includes/template.php b/wp-admin/includes/template.php
index b0865a9c0..b3bdb9d52 100644
--- a/wp-admin/includes/template.php
+++ b/wp-admin/includes/template.php
@@ -1394,7 +1394,7 @@ var userSettings = {
 		'uid': '<?php if ( ! isset($current_user) ) $current_user = wp_get_current_user(); echo $current_user->ID; ?>',
 		'time':'<?php echo time() ?>'
 	},
-	ajaxurl = '<?php echo admin_url('admin-ajax.php'); ?>',
+	ajaxurl = '<?php echo admin_url( 'admin-ajax.php', 'relative' ); ?>',
 	pagenow = '<?php echo $current_screen->id; ?>',
 	typenow = '<?php echo $current_screen->post_type; ?>',
 	adminpage = '<?php echo $admin_body_class; ?>',
diff --git a/wp-admin/press-this.php b/wp-admin/press-this.php
index 60fd1bcc1..08a38c2c7 100644
--- a/wp-admin/press-this.php
+++ b/wp-admin/press-this.php
@@ -304,7 +304,7 @@ die;
 //<![CDATA[
 addLoadEvent = function(func){if(typeof jQuery!="undefined")jQuery(document).ready(func);else if(typeof wpOnload!='function'){wpOnload=func;}else{var oldonload=wpOnload;wpOnload=function(){oldonload();func();}}};
 var userSettings = {'url':'<?php echo SITECOOKIEPATH; ?>','uid':'<?php if ( ! isset($current_user) ) $current_user = wp_get_current_user(); echo $current_user->ID; ?>','time':'<?php echo time() ?>'};
-var ajaxurl = '<?php echo admin_url('admin-ajax.php'); ?>', pagenow = 'press-this', isRtl = <?php echo (int) is_rtl(); ?>;
+var ajaxurl = '<?php echo admin_url( 'admin-ajax.php', 'relative' ); ?>', pagenow = 'press-this', isRtl = <?php echo (int) is_rtl(); ?>;
 var photostorage = false;
 //]]>
 </script>
diff --git a/wp-includes/class-wp-editor.php b/wp-includes/class-wp-editor.php
index 2eb99052c..e8bd2dc91 100644
--- a/wp-includes/class-wp-editor.php
+++ b/wp-includes/class-wp-editor.php
@@ -584,7 +584,7 @@ final class _WP_Editors {
 		}
 
 		if ( !is_admin() )
-			echo 'var ajaxurl = "' . admin_url('admin-ajax.php') . '";';
+			echo 'var ajaxurl = "' . admin_url( 'admin-ajax.php', 'relative' ) . '";';
 ?>
 	</script>
 <?php
diff --git a/wp-includes/media.php b/wp-includes/media.php
index 89a3f36bd..e3b9008e3 100644
--- a/wp-includes/media.php
+++ b/wp-includes/media.php
@@ -1096,7 +1096,7 @@ class WP_Embed {
 <script type="text/javascript">
 /* <![CDATA[ */
 	jQuery(document).ready(function($){
-		$.get("<?php echo admin_url( 'admin-ajax.php?action=oembed-cache&post=' . $post_ID ); ?>");
+		$.get("<?php echo admin_url( 'admin-ajax.php?action=oembed-cache&post=' . $post_ID, 'relative' ); ?>");
 	});
 /* ]]> */
 </script>