diff --git a/tests/lib/SimpleSAML/Utils/CryptoTest.php b/tests/lib/SimpleSAML/Utils/CryptoTest.php
index f865ef45c61084f0032eae90a2bb8b1f9d62d38f..95887beba6bfa350dcf54af7244223dd832cba22 100644
--- a/tests/lib/SimpleSAML/Utils/CryptoTest.php
+++ b/tests/lib/SimpleSAML/Utils/CryptoTest.php
@@ -391,7 +391,7 @@ PHP;
     {
         $filename = $this->certdir . DIRECTORY_SEPARATOR . 'key';
         $data = 'data';
-        $config = new Configuration(['privatekey' => $filename], 'test');
+        $config = new Configuration(['privatekey' => $filename, 'privatekey_pass' => null], 'test');
         $full_path = true;
 
         file_put_contents($filename, $data);