Index: wp-includes/capabilities.php
===================================================================
--- wp-includes/capabilities.php	(revision 13658)
+++ wp-includes/capabilities.php	(working copy)
@@ -770,7 +770,7 @@
 		global $wpdb;
 		if ( !empty($blog_id) ) {
 			$cap_key = $wpdb->get_blog_prefix( $blog_id );
-			$cap_key. 'capabilities';
+			$cap_key.= 'capabilities';
 		} else {
 			$cap_key = '';
 		}