diff --git a/phpgwapi/inc/class.vfs_stream_wrapper.inc.php b/phpgwapi/inc/class.vfs_stream_wrapper.inc.php
index 6aae8f2ab8..d6d56cb60b 100644
--- a/phpgwapi/inc/class.vfs_stream_wrapper.inc.php
+++ b/phpgwapi/inc/class.vfs_stream_wrapper.inc.php
@@ -293,7 +293,7 @@ class vfs_stream_wrapper implements iface_stream_wrapper
 		{
 			return false;
 		}
-		if ($mode != 'r' && self::url_is_readonly($url))
+		if (str_replace('b', '', $mode) != 'r' && self::url_is_readonly($url))
 		{
 			return false;
 		}