diff --git a/composer.json b/composer.json
index 4b227c6..8f37c4f 100644
--- a/composer.json
+++ b/composer.json
@@ -8,11 +8,13 @@
     ],
     "license": "BSD-3-Clause",
     "require": {
+        "php": "^7.3 || ^8.0",
+        "silverstripe/framework": "^4.10",
         "cwp/cwp": "^2",
         "silverstripe/fulltextsearch": "^3@dev"
     },
     "require-dev": {
-        "sminnee/phpunit": "^5.7",
+        "phpunit/phpunit": "^9.5",
         "squizlabs/php_codesniffer": "^3"
     },
     "autoload": {
diff --git a/tests/CwpSearchPageControllerTest.php b/tests/CwpSearchPageControllerTest.php
index 3a22aa2..447d3f0 100644
--- a/tests/CwpSearchPageControllerTest.php
+++ b/tests/CwpSearchPageControllerTest.php
@@ -14,6 +14,6 @@ public function testIndex()
         $result = $this->get('/search');
 
         $this->assertSame(302, $result->getStatusCode());
-        $this->assertContains('SearchForm', $result->getHeader('Location'));
+        $this->assertStringContainsString('SearchForm', $result->getHeader('Location'));
     }
 }
diff --git a/tests/Extensions/SynonymValidatorTest.php b/tests/Extensions/SynonymValidatorTest.php
index 299c920..d6da732 100644
--- a/tests/Extensions/SynonymValidatorTest.php
+++ b/tests/Extensions/SynonymValidatorTest.php
@@ -12,7 +12,7 @@ class SynonymValidatorTest extends SapphireTest
      */
     protected $validator;
 
-    protected function setUp()
+    protected function setUp(): void
     {
         parent::setUp();