diff --git a/tests/phpunit/tests/functions/_wpCheckExistingFileNames.php b/tests/phpunit/tests/functions/_wpCheckExistingFileNames.php
index 13d6fee1d79d0..8c9482e593f7f 100644
--- a/tests/phpunit/tests/functions/_wpCheckExistingFileNames.php
+++ b/tests/phpunit/tests/functions/_wpCheckExistingFileNames.php
@@ -25,7 +25,7 @@ public function test_wp_check_existing_file_names( $filename, $files, $expected
 	 *
 	 * @return array[]
 	 */
-	public function data_wp_check_existing_file_names() {
+	public static function data_wp_check_existing_file_names() {
 		return array(
 			'no size'                      => array(
 				'filename' => 'filename.php',
diff --git a/tests/phpunit/tests/media/getMediaEmbeddedInContent.php b/tests/phpunit/tests/media/getMediaEmbeddedInContent.php
index 3b146ac3e427f..286abb8d7efb0 100644
--- a/tests/phpunit/tests/media/getMediaEmbeddedInContent.php
+++ b/tests/phpunit/tests/media/getMediaEmbeddedInContent.php
@@ -26,7 +26,7 @@ public function test_returns_expected_media( $content, $types, $expected ) {
 	 *
 	 * @return array[]
 	 */
-	public function data_content() {
+	public static function data_content() {
 		$audio  = '<audio preload="none"><source /></audio>';
 		$video  = '<video preload="none"><source /></video>';
 		$iframe = '<iframe src="https://example.com/embed" width="700"></iframe>';
diff --git a/tests/phpunit/tests/meta.php b/tests/phpunit/tests/meta.php
index 50701b5e6d1b8..daf81b3c3d13c 100644
--- a/tests/phpunit/tests/meta.php
+++ b/tests/phpunit/tests/meta.php
@@ -542,7 +542,7 @@ public function test_get_metadata_with_non_existent_object_id( $expected, $args
 		$this->assertSame( $expected, get_metadata( 'user', ...$args ) );
 	}
 
-	public function data_get_metadata_with_non_existent_object_id() {
+	public static function data_get_metadata_with_non_existent_object_id() {
 		return array(
 			'should return empty array for default `$meta_key` and `$single` values' => array(
 				'expected' => array(),
diff --git a/tests/phpunit/tests/vars.php b/tests/phpunit/tests/vars.php
index c7634b780aaff..7d73618a42799 100644
--- a/tests/phpunit/tests/vars.php
+++ b/tests/phpunit/tests/vars.php
@@ -34,7 +34,7 @@ public function tear_down() {
 	 *
 	 * @return array
 	 */
-	public function get_data_to_test_wp_is_mobile(): array {
+	public static function get_data_to_test_wp_is_mobile(): array {
 		return array(
 			'mobile client hint'                 => array(
 				'headers'  => array(