diff --git a/PHPCI/Helper/CommandExecutor.php b/PHPCI/Helper/CommandExecutor.php
index 0515f83c..b7fc3494 100644
--- a/PHPCI/Helper/CommandExecutor.php
+++ b/PHPCI/Helper/CommandExecutor.php
@@ -45,6 +45,8 @@ class CommandExecutor
      */
     public function executeCommand($args = array())
     {
+        $this->lastOutput = array();
+
         $command = call_user_func_array('sprintf', $args);
 
         if ($this->quiet) {