diff --git a/core/tests/Drupal/Tests/Core/Extension/ExtensionListTest.php b/core/tests/Drupal/Tests/Core/Extension/ExtensionListTest.php
index 80a0c76..d0450ab 100644
--- a/core/tests/Drupal/Tests/Core/Extension/ExtensionListTest.php
+++ b/core/tests/Drupal/Tests/Core/Extension/ExtensionListTest.php
@@ -9,6 +9,7 @@
 use Drupal\Core\Extension\ExtensionList;
 use Drupal\Core\Extension\InfoParserInterface;
 use Drupal\Core\Extension\ModuleHandlerInterface;
+use Drupal\Core\Extension\UnknownExtensionException;
 use Drupal\Core\State\StateInterface;
 use Drupal\Tests\UnitTestCase;
 use org\bovigo\vfs\vfsStream;
@@ -31,7 +32,7 @@ public function testGetNameWithNonExistingExtension() {
     $extension_discovery->scan('test_extension')->willReturn([]);
     $test_extension_list->setExtensionDiscovery($extension_discovery->reveal());
 
-    $this->setExpectedException(\InvalidArgumentException::class);
+    $this->setExpectedException(UnknownExtensionException::class);
     $test_extension_list->getName('test_name');
   }
 
@@ -55,7 +56,7 @@ public function testGetWithNonExistingExtension() {
     $extension_discovery->scan('test_extension')->willReturn([]);
     $test_extension_list->setExtensionDiscovery($extension_discovery->reveal());
 
-    $this->setExpectedException(\InvalidArgumentException::class);
+    $this->setExpectedException(UnknownExtensionException::class);
     $test_extension_list->get('test_name');
   }
 
diff --git a/core/tests/Drupal/Tests/Core/Extension/ModuleHandlerTest.php b/core/tests/Drupal/Tests/Core/Extension/ModuleHandlerTest.php
index 4fda002..13d3e93 100644
--- a/core/tests/Drupal/Tests/Core/Extension/ModuleHandlerTest.php
+++ b/core/tests/Drupal/Tests/Core/Extension/ModuleHandlerTest.php
@@ -5,6 +5,7 @@
 use Drupal\Core\Cache\CacheBackendInterface;
 use Drupal\Core\Extension\Extension;
 use Drupal\Core\Extension\ModuleHandler;
+use Drupal\Core\Extension\UnknownExtensionException;
 use Drupal\Tests\UnitTestCase;
 
 /**
@@ -164,7 +165,7 @@ public function testGetModuleWithExistingModule() {
    * @covers ::getModule
    */
   public function testGetModuleWithNonExistingModule() {
-    $this->setExpectedException(\InvalidArgumentException::class);
+    $this->setExpectedException(UnknownExtensionException::class);
     $this->getModuleHandler()->getModule('claire_alice_watch_my_little_pony_module_that_does_not_exist');
   }