diff --git a/lib/GpioPin.php b/lib/GpioPin.php
index 3ed9b07..10e43da 100644
--- a/lib/GpioPin.php
+++ b/lib/GpioPin.php
@@ -46,6 +46,7 @@ class GpioPin
     {
         $this->pin = (int)$pin;
         $this->export();
+        $this->fd = fopen("/sys/class/gpio/gpio{$pin}/value", "rb");
     }
     
     public function __destruct()