diff --git a/core/tests/Drupal/Tests/Component/DependencyInjection/ContainerTest.php b/core/tests/Drupal/Tests/Component/DependencyInjection/ContainerTest.php
index f4cb5ec47f..f2fc10dd7b 100644
--- a/core/tests/Drupal/Tests/Component/DependencyInjection/ContainerTest.php
+++ b/core/tests/Drupal/Tests/Component/DependencyInjection/ContainerTest.php
@@ -94,6 +94,7 @@ public function testGetParameter() {
    */
   public function testGetParameterIfNotFound() {
     $this->expectException(ParameterNotFoundException::class);
+    $this->container->getParameter('parameter_that_does_not_exist');
   }
 
   /**
diff --git a/core/tests/Drupal/Tests/Component/Serialization/YamlTest.php b/core/tests/Drupal/Tests/Component/Serialization/YamlTest.php
index 33250b304b..ffa92efd66 100644
--- a/core/tests/Drupal/Tests/Component/Serialization/YamlTest.php
+++ b/core/tests/Drupal/Tests/Component/Serialization/YamlTest.php
@@ -102,7 +102,13 @@ public function testObjectSupportDisabledPecl() {
    * @see \Drupal\Tests\Component\Serialization\YamlTest::testObjectSupportDisabledPecl()
    */
   public function testObjectSupportDisabledSymfony() {
-    $this->setExpectedExceptionRegExp(InvalidDataTypeException::class, '/^Object support when parsing a YAML file has been disabled/');
+    if (method_exists($this, 'setExpectedExceptionRegExp')) {
+      $this->setExpectedExceptionRegExp(InvalidDataTypeException::class, '/^Object support when parsing a YAML file has been disabled/');
+    }
+    else {
+      $this->expectException(InvalidDataTypeException::class);
+      $this->expectExceptionMessageRegExp('/^Object support when parsing a YAML file has been disabled/');
+    }
     $object = new \stdClass();
     $object->foo = 'bar';
     // In core all Yaml encoding is done via Symfony and it does not support