diff --git a/module/VuFind/src/VuFindTest/Unit/TestCase.php b/module/VuFind/src/VuFindTest/Unit/TestCase.php
index 3dd9ff53eef41bea5a587a9f056cc2bc9301b3f7..eed2055534bf532694622cdb8dd858780b752557 100644
--- a/module/VuFind/src/VuFindTest/Unit/TestCase.php
+++ b/module/VuFind/src/VuFindTest/Unit/TestCase.php
@@ -145,56 +145,57 @@ abstract class TestCase extends \PHPUnit\Framework\TestCase
                 $this->serviceManager,
                 [
                     'abstract_factories' =>
-                        ['VuFind\Search\Options\PluginFactory'],
+                        [\VuFind\Search\Options\PluginFactory::class],
                 ]
             );
             $this->serviceManager->setService(
-                'VuFind\Search\Options\PluginManager', $optionsFactory
+                \VuFind\Search\Options\PluginManager::class, $optionsFactory
             );
             $paramsFactory = new \VuFind\Search\Params\PluginManager(
                 $this->serviceManager,
                 [
                     'abstract_factories' =>
-                        ['VuFind\Search\Params\PluginFactory'],
+                        [\VuFind\Search\Params\PluginFactory::class],
                 ]
             );
             $this->serviceManager->setService(
-                'VuFind\Search\Params\PluginManager', $paramsFactory
+                \VuFind\Search\Params\PluginManager::class, $paramsFactory
             );
             $resultsFactory = new \VuFind\Search\Results\PluginManager(
                 $this->serviceManager,
                 [
                     'abstract_factories' =>
-                        ['VuFind\Search\Results\PluginFactory'],
+                        [\VuFind\Search\Results\PluginFactory::class],
                 ]
             );
             $this->serviceManager->setService(
-                'VuFind\Search\Results\PluginManager', $resultsFactory
+                \VuFind\Search\Results\PluginManager::class, $resultsFactory
             );
             $recordDriverFactory = new \VuFind\RecordDriver\PluginManager(
                 $this->serviceManager,
                 [
                     'abstract_factories' =>
-                        ['VuFind\RecordDriver\PluginFactory']
+                        [\VuFind\RecordDriver\PluginFactory::class]
                 ]
             );
             $this->serviceManager->setService(
-                'VuFind\RecordDriver\PluginManager', $recordDriverFactory
+                \VuFind\RecordDriver\PluginManager::class, $recordDriverFactory
             );
             $this->serviceManager->setService(
-                'VuFind\Config\SearchSpecsReader',
+                \VuFind\Config\SearchSpecsReader::class,
                 new \VuFind\Config\SearchSpecsReader()
             );
             $this->serviceManager->setService(
-                'VuFind\Log\Logger', $this->createMock(\VuFind\Log\Logger::class)
+                \VuFind\Log\Logger::class,
+                $this->createMock(\VuFind\Log\Logger::class)
             );
             $this->serviceManager->setService(
-                'VuFindHttp\HttpService', new \VuFindHttp\HttpService()
+                \VuFindHttp\HttpService::class, new \VuFindHttp\HttpService()
             );
             $this->setupSearchService();
-            $cfg = ['abstract_factories' => ['VuFind\Config\PluginFactory']];
+            $cfg = ['abstract_factories' => [\VuFind\Config\PluginFactory::class]];
             $this->serviceManager->setService(
-                'VuFind\Config\PluginManager',
+                \VuFind\Config\PluginManager::class,
                 new \VuFind\Config\PluginManager($this->serviceManager, $cfg)
             );
             $this->serviceManager->setService(
@@ -203,7 +204,7 @@ abstract class TestCase extends \PHPUnit\Framework\TestCase
             $driverManager = $this->serviceManager
                 ->get(\VuFind\RecordDriver\PluginManager::class);
             $this->serviceManager->setService(
-                'VuFind\Record\Loader', new \VuFind\Record\Loader(
+                \VuFind\Record\Loader::class, new \VuFind\Record\Loader(
                     $this->serviceManager->get(\VuFindSearch\Service::class),
                     $driverManager
                 )
@@ -211,7 +212,7 @@ abstract class TestCase extends \PHPUnit\Framework\TestCase
             $this->serviceManager->setService('Config', []);
             $factory = new \Zend\Mvc\I18n\TranslatorFactory();
             $this->serviceManager->setService(
-                'Zend\Mvc\I18n\Translator',
+                \Zend\Mvc\I18n\Translator::class,
                 $factory->createService($this->serviceManager)
             );
         }