diff --git a/phpseclib/Net/SSH2.php b/phpseclib/Net/SSH2.php
index 263f347b..0854d495 100644
--- a/phpseclib/Net/SSH2.php
+++ b/phpseclib/Net/SSH2.php
@@ -1560,11 +1560,15 @@ class Net_SSH2 {
     /**
      * Execute Command
      *
+     * If $block is set to false then Net_SSH2::_get_channel_packet(NET_SSH2_CHANNEL_EXEC) will need to be called manually.
+     * In all likelihood, this is not a feature you want to be taking advantage of.
+     *
      * @param String $command
+     * @param optional Boolean $block
      * @return String
      * @access public
      */
-    function exec($command)
+    function exec($command, $block = true)
     {
         if (!($this->bitmap & NET_SSH2_MASK_LOGIN)) {
             return false;
@@ -1617,6 +1621,10 @@ class Net_SSH2 {
 
         $this->channel_status[NET_SSH2_CHANNEL_EXEC] = NET_SSH2_MSG_CHANNEL_DATA;
 
+        if (!$block) {
+            return true;
+        }
+
         $output = '';
         while (true) {
             $temp = $this->_get_channel_packet(NET_SSH2_CHANNEL_EXEC);