diff --git a/lib/Doctrine/Cache/Apcu.php b/lib/Doctrine/Cache/Apcu.php
index 394e12c7..0c6d1ec2 100644
--- a/lib/Doctrine/Cache/Apcu.php
+++ b/lib/Doctrine/Cache/Apcu.php
@@ -60,7 +60,7 @@ protected function _doContains($id)
 
     protected function _doSave($id, $data, $lifeTime = false)
     {
-        if ($lifeTime === false) {
+        if ($lifeTime === false || $lifeTime === null) {
             $lifeTime = 0;
         }