diff --git a/composer.json b/composer.json
index 610e38d..80d30c7 100644
--- a/composer.json
+++ b/composer.json
@@ -29,7 +29,7 @@
     },
     "require-dev": {
         "composer/composer": "^2",
-        "phpunit/phpunit": "^11.3",
+        "phpunit/phpunit": "^9.6",
         "squizlabs/php_codesniffer": "^3.7"
     }
 }
diff --git a/tests/Methods/LibraryTest.php b/tests/Methods/LibraryTest.php
index da40e53..1d92c2b 100644
--- a/tests/Methods/LibraryTest.php
+++ b/tests/Methods/LibraryTest.php
@@ -4,11 +4,12 @@
 
 use PHPUnit\Framework\TestCase;
 use SilverStripe\VendorPlugin\Library;
-use PHPUnit\Framework\Attributes\DataProvider;
 
 class LibraryTest extends TestCase
 {
-    #[DataProvider('resourcesDirProvider')]
+    /**
+     * @dataProvider resourcesDirProvider
+     */
     public function testResourcesDir($expected, $projectPath)
     {
         $path = __DIR__ . '/../fixtures/projects/' . $projectPath;
@@ -16,7 +17,7 @@ public function testResourcesDir($expected, $projectPath)
         $this->assertEquals($expected, $lib->getResourcesDir());
     }
 
-    public static function resourcesDirProvider()
+    public function resourcesDirProvider()
     {
         return [
             ['_resources', 'ss43'],