diff --git a/wp-includes/post.php b/wp-includes/post.php
index 3b3d55fe19..37f97d97fb 100644
--- a/wp-includes/post.php
+++ b/wp-includes/post.php
@@ -3703,7 +3703,7 @@ function wp_unique_post_slug( $slug, $post_ID, $post_status, $post_type, $post_p
 		 * Page slugs must be unique within their own trees. Pages are in a separate
 		 * namespace than posts so page slugs are allowed to overlap post slugs.
 		 */
-		$check_sql = "SELECT post_name FROM $wpdb->posts WHERE post_name = %s AND post_type = %s AND ID != %d AND post_parent = %d LIMIT 1";
+		$check_sql = "SELECT post_name FROM $wpdb->posts WHERE post_name = %s AND post_type IN ( %s, 'attachment' ) AND ID != %d AND post_parent = %d LIMIT 1";
 		$post_name_check = $wpdb->get_var( $wpdb->prepare( $check_sql, $slug, $post_type, $post_ID, $post_parent ) );
 
 		/**
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 17c5e0c09c..c24b312ce0 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.1-beta2-30628';
+$wp_version = '4.1-beta2-30629';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.