diff --git a/phpseclib/Net/SFTP/Stream.php b/phpseclib/Net/SFTP/Stream.php
index a944d7f0..4ec80996 100644
--- a/phpseclib/Net/SFTP/Stream.php
+++ b/phpseclib/Net/SFTP/Stream.php
@@ -197,7 +197,7 @@ class Net_SFTP_Stream
 
         if ($host[0] == '$') {
             $host = substr($host, 1);
-            global $$host;
+            global ${$host};
             if (!is_object($$host) || get_class($$host) != 'Net_SFTP') {
                 return false;
             }