diff --git a/tests/lib/Traits/ClientServiceTrait.php b/tests/lib/Traits/ClientServiceTrait.php
index e9e9787d73..60313d5fa7 100644
--- a/tests/lib/Traits/ClientServiceTrait.php
+++ b/tests/lib/Traits/ClientServiceTrait.php
@@ -39,7 +39,7 @@ trait ClientServiceTrait {
 	 * @param string $originalClassName
 	 * @return \PHPUnit\Framework\MockObject\MockObject
 	 */
-	abstract protected function createMock($originalClassName);
+	abstract protected function createMock(string $originalClassName);
 
 	/**
 	 * Returns a matcher that matches when the method is executed
@@ -49,7 +49,7 @@ trait ClientServiceTrait {
 	 *
 	 * @since  Method available since Release 3.0.0
 	 */
-	abstract public function any();
+	abstract static public function any();
 
 	protected function setUpClientServiceTrait() {
 		$this->clientService = $this->createMock(IClientService::class);
diff --git a/tests/lib/Traits/EncryptionTrait.php b/tests/lib/Traits/EncryptionTrait.php
index 38ba18fdfb..f0bbb138d4 100644
--- a/tests/lib/Traits/EncryptionTrait.php
+++ b/tests/lib/Traits/EncryptionTrait.php
@@ -24,8 +24,8 @@ trait EncryptionTrait {
 	abstract protected function registerStorageWrapper($name, $wrapper);
 
 	// from phpunit
-	abstract protected function markTestSkipped(string $message = ''): void;
-	abstract protected function assertTrue($condition, string $message = ''): void;
+	abstract static protected function markTestSkipped(string $message = ''): void;
+	abstract static protected function assertTrue($condition, string $message = ''): void;
 
 	private $encryptionWasEnabled;