diff --git a/src/Config.php b/src/Config.php
index ff1a7b6..58c2697 100644
--- a/src/Config.php
+++ b/src/Config.php
@@ -132,7 +132,7 @@ public function setProperty($key, $value)
 
     public function getProperty($key)
     {
-        if (!isset($this->properties)) {
+        if (!isset($this->properties[$key])) {
             return null;
         }
         return $this->properties[$key];