diff --git a/lam/tests/lib/2factorWebauthnTest.php b/lam/tests/lib/2factorWebauthnTest.php
index 7f0cd39b..c8b77457 100644
--- a/lam/tests/lib/2factorWebauthnTest.php
+++ b/lam/tests/lib/2factorWebauthnTest.php
@@ -37,7 +37,7 @@ class WebauthnProviderTest extends TestCase {
 	 */
 	private $config;
 
-	protected function setUp() {
+	protected function setUp(): void {
 		$this->config = new TwoFactorConfiguration();
 	}