diff --git a/src/Psy/Configuration.php b/src/Psy/Configuration.php
index 6517a7bf6..2761f4264 100644
--- a/src/Psy/Configuration.php
+++ b/src/Psy/Configuration.php
@@ -110,7 +110,7 @@ public function __construct(array $config = array())
      */
     public function setRegisterPlugins($bool)
     {
-        $this->registerPlugins = $bool;
+        $this->registerPlugins = (bool) $bool;
     }
 
     /**