diff --git a/composer.json b/composer.json
index 54407a7..a8182fa 100644
--- a/composer.json
+++ b/composer.json
@@ -19,13 +19,14 @@
         }
     ],
     "require": {
-        "silverstripe/framework": "^4.4",
+        "php": "^7.3 || ^8.0",
+        "silverstripe/framework": "^4.10",
         "silverstripe/reports": "^4.4",
         "symbiote/silverstripe-queuedjobs": "^4",
         "guzzlehttp/guzzle": "^6.3"
     },
     "require-dev": {
-        "sminnee/phpunit": "^5.7",
+        "phpunit/phpunit": "^9.5",
         "squizlabs/php_codesniffer": "^3",
         "symfony/thanks": "^1.0"
     },
@@ -36,9 +37,6 @@
         }
     },
     "extra": {
-        "branch-alias": {
-            "dev-master": "2.x-dev"
-        },
         "expose": [
             "client/dist"
         ]
diff --git a/tests/Forms/GridFieldLinkButtonTest.php b/tests/Forms/GridFieldLinkButtonTest.php
index cfbdadc..6dac37f 100644
--- a/tests/Forms/GridFieldLinkButtonTest.php
+++ b/tests/Forms/GridFieldLinkButtonTest.php
@@ -15,6 +15,6 @@ public function testCorrectLinkIsContained()
         $button = new GridFieldLinkButton('https://addons.silverstripe.org', 'Explore Addons', 'test');
         $output = $button->getHTMLFragments(null);
 
-        $this->assertContains('https://addons.silverstripe.org', $output['test']);
+        $this->assertStringContainsString('https://addons.silverstripe.org', $output['test']);
     }
 }
diff --git a/tests/Forms/GridFieldRefreshButtonTest.php b/tests/Forms/GridFieldRefreshButtonTest.php
index caa75dd..34eb563 100644
--- a/tests/Forms/GridFieldRefreshButtonTest.php
+++ b/tests/Forms/GridFieldRefreshButtonTest.php
@@ -14,7 +14,7 @@ class GridFieldRefreshButtonTest extends SapphireTest
 {
     protected static $fixture_file = 'GridFieldRefreshButtonTest.yml';
 
-    protected function setUp()
+    protected function setUp(): void
     {
         parent::setUp();
 
@@ -68,7 +68,7 @@ public function testHandleRefreshCreatesJobWhenNoJobIsRunning()
     public function testHandleCheckReturnsValidJson()
     {
         $button = $this->getButton();
-        $this->assertSame('true', $button->handleCheck());
+        $this->assertStringContainsString('true', $button->handleCheck());
     }
 
     public function testButtonIsDisabledWhenJobIsRunning()
@@ -79,7 +79,7 @@ public function testButtonIsDisabledWhenJobIsRunning()
 
         $output = $button->getHTMLFragments($gridFieldMock);
 
-        $this->assertContains('disabled', $output['test']);
+        $this->assertStringContainsString('disabled', $output['test']);
     }
 
     public function testButtonIsEnabledWhenNoJobIsRunning()
@@ -92,7 +92,7 @@ public function testButtonIsEnabledWhenNoJobIsRunning()
 
         $output = $button->getHTMLFragments($gridFieldMock);
 
-        $this->assertNotContains('disabled', $output['test']);
+        $this->assertStringNotContainsString('disabled', $output['test']);
     }
 
     /**
diff --git a/tests/Reports/SiteSummaryTest.php b/tests/Reports/SiteSummaryTest.php
index 0d2e3db..1b97306 100644
--- a/tests/Reports/SiteSummaryTest.php
+++ b/tests/Reports/SiteSummaryTest.php
@@ -20,7 +20,7 @@ class SiteSummaryTest extends SapphireTest
         ],
     ];
 
-    protected function setUp()
+    protected function setUp(): void
     {
         parent::setUp();
 
@@ -52,6 +52,6 @@ public function testAlertsRenderAtopTheReportField()
         $fields = $summaryReport->getCMSFields();
         $alertSummary = $fields->fieldByName('AlertSummary');
         $this->assertInstanceOf(LiteralField::class, $alertSummary);
-        $this->assertContains('Sound the alarm!', $alertSummary->getContent());
+        $this->assertStringContainsString('Sound the alarm!', $alertSummary->getContent());
     }
 }
diff --git a/tests/Tasks/UpdatePackageInfoTest.php b/tests/Tasks/UpdatePackageInfoTest.php
index e81e743..b2d4024 100644
--- a/tests/Tasks/UpdatePackageInfoTest.php
+++ b/tests/Tasks/UpdatePackageInfoTest.php
@@ -47,7 +47,7 @@ public function testGetPackageInfo()
         /** @var UpdatePackageInfoTask $processor */
         $processor = UpdatePackageInfoTask::create();
         $output = $processor->getPackageInfo($lockOutput);
-        $this->assertInternalType('array', $output);
+        $this->assertIsArray($output);
         $this->assertCount(1, $output);
         $this->assertContains([
             "Name" => "fake/package",
@@ -74,7 +74,7 @@ public function testGetSupportedPackagesEchosErrors()
         $task->getSupportedPackages();
         $output = ob_get_clean();
 
-        $this->assertContains('A test message', $output);
+        $this->assertStringContainsString('A test message', $output);
     }
 
     public function testPackagesAreAddedCorrectly()
diff --git a/tests/Util/ApiLoaderTest.php b/tests/Util/ApiLoaderTest.php
index 00e9e4f..023ff2d 100644
--- a/tests/Util/ApiLoaderTest.php
+++ b/tests/Util/ApiLoaderTest.php
@@ -2,6 +2,7 @@
 
 namespace BringYourOwnIdeas\Maintenance\Tests\Util;
 
+use RuntimeException;
 use BringYourOwnIdeas\Maintenance\Util\ApiLoader;
 use GuzzleHttp\Client;
 use GuzzleHttp\Handler\MockHandler;
@@ -12,12 +13,10 @@
 
 class ApiLoaderTest extends SapphireTest
 {
-    /**
-     * @expectedException RuntimeException
-     * @expectedExceptionMessage Could not obtain information about module. Error code 404
-     */
     public function testNon200ErrorCodesAreHandled()
     {
+        $this->expectException(RuntimeException::class);
+        $this->expectExceptionMessage('Could not obtain information about module. Error code 404');
         $loader = $this->getLoader();
         $loader->setGuzzleClient($this->getMockClient(new Response(404)));
 
@@ -26,12 +25,10 @@ public function testNon200ErrorCodesAreHandled()
         });
     }
 
-    /**
-     * @expectedException RuntimeException
-     * @expectedExceptionMessage Could not obtain information about module. Response is not JSON
-     */
     public function testNonJsonResponsesAreHandled()
     {
+        $this->expectException(RuntimeException::class);
+        $this->expectExceptionMessage('Could not obtain information about module. Response is not JSON');
         $loader = $this->getLoader();
         $loader->setGuzzleClient($this->getMockClient(new Response(
             200,
@@ -43,12 +40,10 @@ public function testNonJsonResponsesAreHandled()
         });
     }
 
-    /**
-     * @expectedException RuntimeException
-     * @expectedExceptionMessage Could not obtain information about module. Response returned unsuccessfully
-     */
     public function testUnsuccessfulResponsesAreHandled()
     {
+        $this->expectException(RuntimeException::class);
+        $this->expectExceptionMessage('Could not obtain information about module. Response returned unsuccessfully');
         $loader = $this->getLoader();
         $loader->setGuzzleClient($this->getMockClient(new Response(
             200,
diff --git a/tests/Util/ModuleHealthLoaderTest.php b/tests/Util/ModuleHealthLoaderTest.php
index 00634c4..c6ed3df 100644
--- a/tests/Util/ModuleHealthLoaderTest.php
+++ b/tests/Util/ModuleHealthLoaderTest.php
@@ -10,7 +10,7 @@ class ModuleHealthLoaderTest extends SapphireTest
      */
     protected $loader;
 
-    protected function setUp()
+    protected function setUp(): void
     {
         parent::setUp();
 
diff --git a/tests/Util/SupportedAddonsLoaderTest.php b/tests/Util/SupportedAddonsLoaderTest.php
index 4156996..51e5674 100644
--- a/tests/Util/SupportedAddonsLoaderTest.php
+++ b/tests/Util/SupportedAddonsLoaderTest.php
@@ -12,7 +12,7 @@ class SupportedAddonsLoaderTest extends SapphireTest
      */
     protected $loader;
 
-    protected function setUp()
+    protected function setUp(): void
     {
         parent::setUp();