diff --git a/wp-admin/edit-form-advanced.php b/wp-admin/edit-form-advanced.php
index 26b0cd96bf..ebda7a3f69 100644
--- a/wp-admin/edit-form-advanced.php
+++ b/wp-admin/edit-form-advanced.php
@@ -504,7 +504,7 @@ if ( post_type_supports($post_type, 'editor') ) {
 <?php wp_editor( $post->post_content, 'content', array(
 	'dfw' => true,
 	'drag_drop_upload' => true,
-	'tabfocus_elements' => 'insert-media-button-1,save-post',
+	'tabfocus_elements' => 'insert-media-button,save-post',
 	'editor_height' => 300,
 	'tinymce' => array(
 		'resize' => false,
diff --git a/wp-admin/includes/media.php b/wp-admin/includes/media.php
index 3c30cd686e..2b9d5eb124 100644
--- a/wp-admin/includes/media.php
+++ b/wp-admin/includes/media.php
@@ -528,8 +528,9 @@ function media_buttons($editor_id = 'content') {
 
 	$img = '<span class="wp-media-buttons-icon"></span> ';
 
-	printf( '<a href="#" id="insert-media-button-%d" class="button insert-media add_media" data-editor="%s" title="%s">%s</a>',
-		$instance,
+	$id_attribute = $instance === 1 ? ' id="insert-media-button"' : '';
+	printf( '<a href="#"%s class="button insert-media add_media" data-editor="%s" title="%s">%s</a>',
+		$id_attribute,
 		esc_attr( $editor_id ),
 		esc_attr__( 'Add Media' ),
 		$img . __( 'Add Media' )