diff --git a/tests/lib/SimpleSAML/Utils/CryptoTest.php b/tests/lib/SimpleSAML/Utils/CryptoTest.php
index 044eacbda07d87b189b81359d51971524033bd1e..90b2f71cf0445b080434473f39e152c5b02bf7d1 100644
--- a/tests/lib/SimpleSAML/Utils/CryptoTest.php
+++ b/tests/lib/SimpleSAML/Utils/CryptoTest.php
@@ -174,7 +174,7 @@ PHP;
 
         $hash = Crypto::pwHash($pw);
         $this->expectException(Error\Exception::class);
-        $res = Crypto::pwValid($hash, $hash);
+        Crypto::pwValid($hash, $hash);
     }