diff --git a/.gitignore b/.gitignore
index 81be26977..1e99c41a5 100644
--- a/.gitignore
+++ b/.gitignore
@@ -17,6 +17,7 @@ nbproject/*
 .svn
 errors.err
 tags
+/.phpunit.result.cache
 /nbproject/
 /composer.lock
 /vendor
diff --git a/.travis.yml b/.travis.yml
index 075881bbf..60e129fbd 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,8 +1,8 @@
 language: php
 
 php:
-  - 7.1
   - 7.2
+  - 7.3
 
 dist: trusty
 
diff --git a/composer.json b/composer.json
index af053ad9d..3fe83ac5c 100644
--- a/composer.json
+++ b/composer.json
@@ -31,7 +31,7 @@
     },
     "require-dev": {
         "cakephp/cakephp-codesniffer": "dev-next",
-        "phpunit/phpunit": "^7.0"
+        "phpunit/phpunit": "^8.0"
     },
     "autoload": {
         "psr-4": {
diff --git a/src/Controller/MailPreviewController.php b/src/Controller/MailPreviewController.php
index c790bb0e8..f4619d554 100644
--- a/src/Controller/MailPreviewController.php
+++ b/src/Controller/MailPreviewController.php
@@ -122,7 +122,7 @@ public function email($name, $method)
         $email = $this->findPreview($name, $method, $plugin);
         $partType = $this->request->getQuery('part');
 
-        $this->viewBuilder()->setLayout(false);
+        $this->viewBuilder()->disableAutoLayout();
 
         if ($partType) {
             return $this->respondWithPart($email, $partType);
diff --git a/tests/TestCase/Cache/Engine/DebugEngineTest.php b/tests/TestCase/Cache/Engine/DebugEngineTest.php
index 9b57ae5b1..8cd8f67b8 100644
--- a/tests/TestCase/Cache/Engine/DebugEngineTest.php
+++ b/tests/TestCase/Cache/Engine/DebugEngineTest.php
@@ -14,6 +14,7 @@
  */
 namespace DebugKit\Test\TestCase\Cache\Engine;
 
+use BadMethodCallException;
 use Cake\TestSuite\TestCase;
 use DebugKit\Cache\Engine\DebugEngine;
 use DebugKit\DebugTimer;
@@ -38,7 +39,7 @@ class DebugEngineTest extends TestCase
      *
      * @return void
      */
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
         $mock = $this->getMockBuilder('Cake\Cache\CacheEngine')->getMock();
@@ -66,11 +67,11 @@ public function testInitEngineBasedOnConfig()
     /**
      * Test that the normal errors bubble up still.
      *
-     * @expectedException BadMethodCallException
      * @return void
      */
     public function testInitErrorOnInvalidConfig()
     {
+        $this->expectException(BadMethodCallException::class);
         $engine = new DebugEngine([
             'className' => 'Derpy',
             'path' => TMP,
diff --git a/tests/TestCase/Controller/MailPreviewControllerTest.php b/tests/TestCase/Controller/MailPreviewControllerTest.php
index 8b0cd81b7..5feaa240c 100644
--- a/tests/TestCase/Controller/MailPreviewControllerTest.php
+++ b/tests/TestCase/Controller/MailPreviewControllerTest.php
@@ -40,7 +40,7 @@ class MailPreviewControllerTest extends IntegrationTestCase
      *
      * @return void
      */
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
 
diff --git a/tests/TestCase/Controller/PanelsControllerTest.php b/tests/TestCase/Controller/PanelsControllerTest.php
index c2c233767..bdb93abb0 100644
--- a/tests/TestCase/Controller/PanelsControllerTest.php
+++ b/tests/TestCase/Controller/PanelsControllerTest.php
@@ -38,7 +38,7 @@ class PanelsControllerTest extends IntegrationTestCase
      *
      * @return void
      */
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
         Router::plugin('DebugKit', function (RouteBuilder $routes) {
diff --git a/tests/TestCase/Controller/RequestsControllerTest.php b/tests/TestCase/Controller/RequestsControllerTest.php
index 2d9eef978..f1484dfd1 100644
--- a/tests/TestCase/Controller/RequestsControllerTest.php
+++ b/tests/TestCase/Controller/RequestsControllerTest.php
@@ -38,7 +38,7 @@ class RequestsControllerTest extends IntegrationTestCase
      *
      * @return void
      */
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
         Router::plugin('DebugKit', function (RouteBuilder $routes) {
diff --git a/tests/TestCase/Controller/ToolbarControllerTest.php b/tests/TestCase/Controller/ToolbarControllerTest.php
index f4dad2d0f..0407d93da 100644
--- a/tests/TestCase/Controller/ToolbarControllerTest.php
+++ b/tests/TestCase/Controller/ToolbarControllerTest.php
@@ -39,7 +39,7 @@ class ToolbarControllerTest extends IntegrationTestCase
      *
      * @return void
      */
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
         Router::plugin('DebugKit', function (RouteBuilder $routes) {
diff --git a/tests/TestCase/Database/Log/DebugLogTest.php b/tests/TestCase/Database/Log/DebugLogTest.php
index 09daa8a49..1230f3a84 100644
--- a/tests/TestCase/Database/Log/DebugLogTest.php
+++ b/tests/TestCase/Database/Log/DebugLogTest.php
@@ -32,7 +32,7 @@ class DebugLogTest extends TestCase
      *
      * @return void
      */
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
         $this->logger = new DebugLog(null, 'test');
diff --git a/tests/TestCase/DebugIncludeTest.php b/tests/TestCase/DebugIncludeTest.php
index e7754a6e2..6d1a76cb6 100644
--- a/tests/TestCase/DebugIncludeTest.php
+++ b/tests/TestCase/DebugIncludeTest.php
@@ -26,7 +26,7 @@ public function testIncludePaths()
     {
         $include = new DebugInclude();
         $result = $include->includePaths();
-        $this->assertInternalType('array', $result);
+        $this->assertIsArray($result);
         $this->assertFileExists($result[0]);
     }
 
diff --git a/tests/TestCase/DebugMemoryTest.php b/tests/TestCase/DebugMemoryTest.php
index dd7601748..ca11f3085 100644
--- a/tests/TestCase/DebugMemoryTest.php
+++ b/tests/TestCase/DebugMemoryTest.php
@@ -47,7 +47,7 @@ public function testRecordNoKey()
         DebugMemory::record();
         $result = DebugMemory::getAll(true);
         $this->assertCount(1, $result);
-        $this->assertContains('DebugMemoryTest.php line ' . (__LINE__ - 3), array_keys($result)[0]);
+        $this->assertStringContainsString('DebugMemoryTest.php line ' . (__LINE__ - 3), array_keys($result)[0]);
     }
 
     /**
diff --git a/tests/TestCase/DebugPanelTest.php b/tests/TestCase/DebugPanelTest.php
index 341477b51..ea7f18187 100644
--- a/tests/TestCase/DebugPanelTest.php
+++ b/tests/TestCase/DebugPanelTest.php
@@ -27,7 +27,7 @@ class DebugPanelTest extends TestCase
      */
     protected $panel;
 
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
         $this->panel = new SimplePanel();
diff --git a/tests/TestCase/DebugSqlTest.php b/tests/TestCase/DebugSqlTest.php
index 48008db99..0aac66e7d 100644
--- a/tests/TestCase/DebugSqlTest.php
+++ b/tests/TestCase/DebugSqlTest.php
@@ -34,7 +34,7 @@ class DebugSqlTest extends TestCase
      *
      * @return void
      */
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
         $this->connection = ConnectionManager::get('test');
diff --git a/tests/TestCase/DebugTimerTest.php b/tests/TestCase/DebugTimerTest.php
index 71a229e18..275338e88 100644
--- a/tests/TestCase/DebugTimerTest.php
+++ b/tests/TestCase/DebugTimerTest.php
@@ -28,7 +28,7 @@ class DebugTimerTest extends TestCase
      *
      * @return void
      */
-    public function tearDown()
+    public function tearDown(): void
     {
         DebugTimer::clear();
     }
diff --git a/tests/TestCase/Mailer/Transport/DebugKitTransportTest.php b/tests/TestCase/Mailer/Transport/DebugKitTransportTest.php
index 2bb44d8ea..4132acaa8 100644
--- a/tests/TestCase/Mailer/Transport/DebugKitTransportTest.php
+++ b/tests/TestCase/Mailer/Transport/DebugKitTransportTest.php
@@ -20,7 +20,7 @@
 
 class DebugKitTransportTest extends TestCase
 {
-    public function setUp()
+    public function setUp(): void
     {
         $this->log = new \ArrayObject();
         $this->wrapped = $this->getMockBuilder(AbstractTransport::class)
diff --git a/tests/TestCase/Middleware/DebugKitMiddlewareTest.php b/tests/TestCase/Middleware/DebugKitMiddlewareTest.php
index c22757910..1ffb5c51d 100644
--- a/tests/TestCase/Middleware/DebugKitMiddlewareTest.php
+++ b/tests/TestCase/Middleware/DebugKitMiddlewareTest.php
@@ -44,7 +44,7 @@ class DebugKitMiddlewareTest extends TestCase
      *
      * @return void
      */
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
 
@@ -58,7 +58,7 @@ public function setUp()
      *
      * @return void
      */
-    public function tearDown()
+    public function tearDown(): void
     {
         parent::tearDown();
 
@@ -150,8 +150,8 @@ public function testInvokeNoModifyBinaryResponse()
 
         $this->assertEquals(1, $total, 'Should track response');
         $body = $result->getBody();
-        $this->assertNotContains('__debug_kit', '' . $body);
-        $this->assertNotContains('<script', '' . $body);
+        $this->assertStringNotContainsString('__debug_kit', '' . $body);
+        $this->assertStringNotContainsString('<script', '' . $body);
     }
 
     /**
@@ -216,7 +216,7 @@ public function testInvokeNoModifyRequestAction()
 
         $this->assertEquals(0, $total, 'Should not track sub-requests');
         $body = $result->getBody();
-        $this->assertNotContains('<script', '' . $body);
+        $this->assertStringNotContainsString('<script', '' . $body);
     }
 
     /**
diff --git a/tests/TestCase/Model/Behavior/TimedBehaviorTest.php b/tests/TestCase/Model/Behavior/TimedBehaviorTest.php
index bddd9f759..5c28be4d5 100644
--- a/tests/TestCase/Model/Behavior/TimedBehaviorTest.php
+++ b/tests/TestCase/Model/Behavior/TimedBehaviorTest.php
@@ -40,7 +40,7 @@ class TimedBehaviorTest extends TestCase
      *
      * @return void
      */
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
         $this->Article = TableRegistry::get('Articles');
@@ -52,7 +52,7 @@ public function setUp()
      *
      * @return void
      */
-    public function tearDown()
+    public function tearDown(): void
     {
         parent::tearDown();
         unset($this->Article);
diff --git a/tests/TestCase/Model/Table/RequestTableTest.php b/tests/TestCase/Model/Table/RequestTableTest.php
index e479afc7d..8759faf1f 100644
--- a/tests/TestCase/Model/Table/RequestTableTest.php
+++ b/tests/TestCase/Model/Table/RequestTableTest.php
@@ -31,7 +31,7 @@ class RequestTableTest extends TestCase
      *
      * @return void
      */
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
         $connection = ConnectionManager::get('test');
diff --git a/tests/TestCase/Panel/CachePanelTest.php b/tests/TestCase/Panel/CachePanelTest.php
index 06eb47b38..9d72cbd3d 100644
--- a/tests/TestCase/Panel/CachePanelTest.php
+++ b/tests/TestCase/Panel/CachePanelTest.php
@@ -32,7 +32,7 @@ class CachePanelTest extends TestCase
      *
      * @return void
      */
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
         $this->panel = new CachePanel();
@@ -44,7 +44,7 @@ public function setUp()
      *
      * @return void
      */
-    public function tearDown()
+    public function tearDown(): void
     {
         parent::tearDown();
         Cache::drop('debug_kit_test');
diff --git a/tests/TestCase/Panel/DeprecationsPanelTest.php b/tests/TestCase/Panel/DeprecationsPanelTest.php
index 9c2abcdca..f0a2e9730 100644
--- a/tests/TestCase/Panel/DeprecationsPanelTest.php
+++ b/tests/TestCase/Panel/DeprecationsPanelTest.php
@@ -33,7 +33,7 @@ class DeprecationsPanelTest extends TestCase
      *
      * @return void
      */
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
         DeprecationsPanel::clearDeprecatedErrors();
@@ -64,12 +64,12 @@ public function testShutdown()
         $this->assertCount(3, $data['plugins']['DebugKit']);
 
         $error = $data['plugins']['DebugKit'][0];
-        $this->assertContains('Something going away', $error['message']);
+        $this->assertStringContainsString('Something going away', $error['message']);
         $this->assertEquals('DebugKit/tests/TestCase/Panel/DeprecationsPanelTest.php', $error['niceFile']);
         $this->assertEquals(46, $error['line']);
 
         $error = $data['plugins']['DebugKit'][2];
-        $this->assertContains('Raw error', $error['message']);
+        $this->assertStringContainsString('Raw error', $error['message']);
         $this->assertEquals('DebugKit/tests/TestCase/Panel/DeprecationsPanelTest.php', $error['niceFile']);
         $this->assertEquals(48, $error['line']);
     }
diff --git a/tests/TestCase/Panel/EnvironmentPanelTest.php b/tests/TestCase/Panel/EnvironmentPanelTest.php
index 63aca7539..41342bb90 100644
--- a/tests/TestCase/Panel/EnvironmentPanelTest.php
+++ b/tests/TestCase/Panel/EnvironmentPanelTest.php
@@ -33,7 +33,7 @@ class EnvironmentPanelTest extends TestCase
      *
      * @return void
      */
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
         $this->panel = new EnvironmentPanel();
@@ -44,7 +44,7 @@ public function setUp()
      *
      * @return void
      */
-    public function tearDown()
+    public function tearDown(): void
     {
         parent::tearDown();
         unset($this->panel);
@@ -63,7 +63,7 @@ public function testShutdown()
 
         $this->panel->shutdown($event);
         $output = $this->panel->data();
-        $this->assertInternalType('array', $output);
+        $this->assertIsArray($output);
         $this->assertSame(['php', 'ini', 'cake', 'app'], array_keys($output));
         $this->assertEquals('mysql://user:password@localhost/my_db', $output['php']['TEST_URL_1']);
     }
diff --git a/tests/TestCase/Panel/IncludePanelTest.php b/tests/TestCase/Panel/IncludePanelTest.php
index 35eca4fc6..01ca389a8 100644
--- a/tests/TestCase/Panel/IncludePanelTest.php
+++ b/tests/TestCase/Panel/IncludePanelTest.php
@@ -33,7 +33,7 @@ class IncludePanelTest extends TestCase
      *
      * @return void
      */
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
         $this->panel = new IncludePanel();
diff --git a/tests/TestCase/Panel/LogPanelTest.php b/tests/TestCase/Panel/LogPanelTest.php
index 47cf34881..de992370b 100644
--- a/tests/TestCase/Panel/LogPanelTest.php
+++ b/tests/TestCase/Panel/LogPanelTest.php
@@ -33,7 +33,7 @@ class LogPanelTest extends TestCase
      *
      * @return void
      */
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
         $this->panel = new LogPanel();
@@ -44,7 +44,7 @@ public function setUp()
      *
      * @return void
      */
-    public function tearDown()
+    public function tearDown(): void
     {
         parent::tearDown();
         Log::drop('debug_kit_log_panel');
@@ -77,7 +77,7 @@ public function testData()
         $result = $this->panel->data();
 
         $this->assertArrayHasKey('logger', $result);
-        /* @var DebugKitLog $logger */
+        /** @var DebugKitLog $logger */
         $logger = $result['logger'];
 
         $this->assertInstanceOf('DebugKit\Log\Engine\DebugKitLog', $logger);
diff --git a/tests/TestCase/Panel/PackagesPanelTest.php b/tests/TestCase/Panel/PackagesPanelTest.php
index e88ae4e6e..9c7b00fce 100644
--- a/tests/TestCase/Panel/PackagesPanelTest.php
+++ b/tests/TestCase/Panel/PackagesPanelTest.php
@@ -33,7 +33,7 @@ class PackagesPanelTest extends TestCase
      *
      * @return void
      */
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
         $this->panel = new PackagesPanel();
diff --git a/tests/TestCase/Panel/RoutesPanelTest.php b/tests/TestCase/Panel/RoutesPanelTest.php
index 225bff5b4..50889f335 100644
--- a/tests/TestCase/Panel/RoutesPanelTest.php
+++ b/tests/TestCase/Panel/RoutesPanelTest.php
@@ -34,7 +34,7 @@ class RoutesPanelTest extends TestCase
      *
      * @return void
      */
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
 
diff --git a/tests/TestCase/Panel/SqlLogPanelTest.php b/tests/TestCase/Panel/SqlLogPanelTest.php
index 24917b272..3710d105b 100644
--- a/tests/TestCase/Panel/SqlLogPanelTest.php
+++ b/tests/TestCase/Panel/SqlLogPanelTest.php
@@ -18,6 +18,7 @@
 use Cake\ORM\TableRegistry;
 use Cake\TestSuite\TestCase;
 use DebugKit\Panel\SqlLogPanel;
+use ReflectionProperty;
 
 /**
  * Class SqlLogPanelTest
@@ -46,14 +47,14 @@ class SqlLogPanelTest extends TestCase
      *
      * @return void
      */
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
         $this->panel = new SqlLogPanel();
         $this->logger = ConnectionManager::get('test')->getLogger();
     }
 
-    public function tearDown()
+    public function tearDown(): void
     {
         parent::tearDown();
         ConnectionManager::get('test')->setLogger($this->logger);
@@ -88,7 +89,10 @@ public function testInitializePassesIncludeSchema()
         $db = ConnectionManager::get('test');
         $logger = $db->getLogger();
         $this->assertInstanceOf('DebugKit\Database\Log\DebugLog', $logger);
-        $this->assertAttributeEquals(true, '_includeSchema', $logger);
+
+        $property = new ReflectionProperty($logger, '_includeSchema');
+        $property->setAccessible(true);
+        $this->assertTrue($property->getValue($logger));
     }
 
     /**
@@ -100,7 +104,7 @@ public function testData()
     {
         $this->panel->initialize();
 
-        /* @var Table $articles */
+        /** @var Table $articles */
         $articles = TableRegistry::get('Articles');
         $articles->findById(1)->first();
 
@@ -117,7 +121,7 @@ public function testSummary()
     {
         $this->panel->initialize();
 
-        /* @var Table $articles */
+        /** @var Table $articles */
         $articles = TableRegistry::get('Articles');
         $articles->findById(1)->first();
 
diff --git a/tests/TestCase/Panel/VariablesPanelTest.php b/tests/TestCase/Panel/VariablesPanelTest.php
index bb3b6fc32..742b81419 100644
--- a/tests/TestCase/Panel/VariablesPanelTest.php
+++ b/tests/TestCase/Panel/VariablesPanelTest.php
@@ -38,7 +38,7 @@ class VariablesPanelTest extends TestCase
      *
      * @return void
      */
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
         $this->panel = new VariablesPanel();
@@ -49,7 +49,7 @@ public function setUp()
      *
      * @return void
      */
-    public function tearDown()
+    public function tearDown(): void
     {
         parent::tearDown();
         unset($this->panel);
@@ -110,7 +110,7 @@ public function testShutdown()
             }
         });
         $this->assertRegExp('/^\[stream\] Resource id #\d+$/', $output['content']['resource']);
-        $this->assertInternalType('array', $output['content']['unserializableDebugInfo']);
+        $this->assertIsArray($output['content']['unserializableDebugInfo']);
         $this->assertStringStartsWith(
             'Unserializable object - stdClass. Error: You cannot serialize or unserialize PDO instances',
             $output['content']['unserializableDebugInfo']['unserializable']
@@ -124,10 +124,10 @@ public function testShutdown()
             $controller->viewBuilder()->getVar('query'),
             'Original value should not be mutated'
         );
-        $this->assertInternalType('array', $output['content']['updateQuery']);
-        $this->assertInternalType('array', $output['content']['query']);
-        $this->assertInternalType('array', $output['content']['unbufferedQuery']);
-        $this->assertInternalType('array', $output['content']['result set']);
+        $this->assertIsArray($output['content']['updateQuery']);
+        $this->assertIsArray($output['content']['query']);
+        $this->assertIsArray($output['content']['unbufferedQuery']);
+        $this->assertIsArray($output['content']['result set']);
         $this->assertEquals($controller->viewBuilder()->getVar('string'), $output['content']['string']);
         $this->assertEquals($controller->viewBuilder()->getVar('array'), $output['content']['array']);
     }
diff --git a/tests/TestCase/ToolbarServiceTest.php b/tests/TestCase/ToolbarServiceTest.php
index ca721014d..fc9a412da 100644
--- a/tests/TestCase/ToolbarServiceTest.php
+++ b/tests/TestCase/ToolbarServiceTest.php
@@ -51,7 +51,7 @@ class ToolbarServiceTest extends TestCase
      *
      * @return void
      */
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
         $this->events = new EventManager();
@@ -65,7 +65,7 @@ public function setUp()
      *
      * @return void
      */
-    public function tearDown()
+    public function tearDown(): void
     {
         parent::tearDown();
         putenv('HTTP_HOST=');
diff --git a/tests/TestCase/View/Helper/CredentialsHelperTest.php b/tests/TestCase/View/Helper/CredentialsHelperTest.php
index 072d53846..0075edf16 100644
--- a/tests/TestCase/View/Helper/CredentialsHelperTest.php
+++ b/tests/TestCase/View/Helper/CredentialsHelperTest.php
@@ -39,7 +39,7 @@ class CredentialsHelperTest extends TestCase
      *
      * @return void
      */
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
 
@@ -54,7 +54,7 @@ public function setUp()
      *
      * @return void
      */
-    public function tearDown()
+    public function tearDown(): void
     {
         parent::tearDown();
         unset($this->Helper);
diff --git a/tests/TestCase/View/Helper/SimpleGraphHelperTest.php b/tests/TestCase/View/Helper/SimpleGraphHelperTest.php
index 94f271feb..884007174 100644
--- a/tests/TestCase/View/Helper/SimpleGraphHelperTest.php
+++ b/tests/TestCase/View/Helper/SimpleGraphHelperTest.php
@@ -40,7 +40,7 @@ class SimpleGraphHelperTest extends TestCase
      *
      * @return void
      */
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
         Router::connect('/:controller/:action');
@@ -57,7 +57,7 @@ public function setUp()
      *
      * @return void
      */
-    public function tearDown()
+    public function tearDown(): void
     {
         parent::tearDown();
         unset($this->Graph);
diff --git a/tests/TestCase/View/Helper/ToolbarHelperTest.php b/tests/TestCase/View/Helper/ToolbarHelperTest.php
index 1ff722230..fa77f7b8b 100644
--- a/tests/TestCase/View/Helper/ToolbarHelperTest.php
+++ b/tests/TestCase/View/Helper/ToolbarHelperTest.php
@@ -41,7 +41,7 @@ class ToolbarHelperTest extends TestCase
      *
      * @return void
      */
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
         Router::connect('/:controller/:action');
@@ -58,7 +58,7 @@ public function setUp()
      *
      * @return void
      */
-    public function tearDown()
+    public function tearDown(): void
     {
         parent::tearDown();
         unset($this->Toolbar);
diff --git a/tests/bootstrap.php b/tests/bootstrap.php
index f8823989f..2207fab30 100644
--- a/tests/bootstrap.php
+++ b/tests/bootstrap.php
@@ -11,6 +11,7 @@
  * @link          http://cakephp.org CakePHP(tm) Project
  * @license       http://www.opensource.org/licenses/mit-license.php MIT License
  */
+
 use Cake\Cache\Cache;
 use Cake\Core\Configure;
 use Cake\Core\Plugin;
@@ -20,6 +21,7 @@
 require_once 'vendor/autoload.php';
 
 // Path constants to a few helpful things.
+define('DS', DIRECTORY_SEPARATOR);
 define('ROOT', dirname(__DIR__));
 define('CAKE_CORE_INCLUDE_PATH', ROOT . DS . 'vendor' . DS . 'cakephp' . DS . 'cakephp');
 define('CORE_PATH', ROOT . DS . 'vendor' . DS . 'cakephp' . DS . 'cakephp' . DS);