diff --git a/phpseclib/Net/SSH2.php b/phpseclib/Net/SSH2.php
index deb92e63..29a8f0f4 100644
--- a/phpseclib/Net/SSH2.php
+++ b/phpseclib/Net/SSH2.php
@@ -1959,7 +1959,7 @@ class Net_SSH2 {
         while (true) {
             if ($mode == NET_SSH2_READ_REGEX) {
                 preg_match($expect, $this->interactiveBuffer, $matches);
-                $match = $matches[0];
+                $match = isset($matches[0]) ? $matches[0] : array();
             }
             $pos = !empty($match) ? strpos($this->interactiveBuffer, $match) : false;
             if ($pos !== false) {