diff --git a/lib/ext/Syncroton/Server.php b/lib/ext/Syncroton/Server.php
--- a/lib/ext/Syncroton/Server.php
+++ b/lib/ext/Syncroton/Server.php
@@ -346,6 +346,11 @@
                 $tag    = ord(fread($stream, 1));
                 $length = ord(fread($stream, 1));
 
+                // If the stream is at the end we'll get a 0-length
+                if (!$length) {
+                    continue;
+                }
+
                 switch ($tag) {
                     case self::PARAMETER_ATTACHMENTNAME:
                         $unpacked = unpack('A' . $length . 'string', fread($stream, $length));