diff --git a/tests/Grant/AuthCodeGrantTest.php b/tests/Grant/AuthCodeGrantTest.php
index a858871a..c72073ec 100644
--- a/tests/Grant/AuthCodeGrantTest.php
+++ b/tests/Grant/AuthCodeGrantTest.php
@@ -48,7 +48,7 @@ class AuthCodeGrantTest extends TestCase
     {
         $this->cryptStub = new CryptTraitStub;
         $this->codeVerifier = rtrim(strtr(base64_encode(random_bytes(32)), '+/', '-_'), '=');
-        $this->codeChallenge = rtrim(strtr(base64_encode(hash('sha256',$this->codeVerifier, true)), '+/', '-_'), '=');
+        $this->codeChallenge = hash('sha256', strtr(rtrim(base64_encode($this->codeVerifier), '='), '+/', '-_'));
     }
 
     public function testGetIdentifier()