diff --git a/tests/Basic/IFrameTest.php b/tests/Basic/IFrameTest.php
index ed7d666..24f14e1 100644
--- a/tests/Basic/IFrameTest.php
+++ b/tests/Basic/IFrameTest.php
@@ -7,13 +7,9 @@
 final class IFrameTest extends TestCase
 {
     /**
-     * @param string $iframeIdentifier
-     * @param string $elementSelector
-     * @param string $elementContent
-     *
      * @dataProvider iFrameDataProvider
      */
-    public function testIFrame($iframeIdentifier, $elementSelector, $elementContent): void
+    public function testIFrame(string $iframeIdentifier, string $elementSelector, string $elementContent): void
     {
         $this->getSession()->visit($this->pathTo('/iframe.html'));
         $webAssert = $this->getAssertSession();
@@ -35,7 +31,7 @@ public function testIFrame($iframeIdentifier, $elementSelector, $elementContent)
     /**
      * @return array
      */
-    public function iFrameDataProvider()
+    public static function iFrameDataProvider()
     {
         return array(
             'by name' => array('subframe_by_name', '#text', 'iFrame div text'),