diff --git a/tests/phpunit/tests/speculative-loading/wpPrintSpeculationRules.php b/tests/phpunit/tests/speculative-loading/wpPrintSpeculationRules.php
index 3945fe16b1a3b..e2887f8b0b6ce 100644
--- a/tests/phpunit/tests/speculative-loading/wpPrintSpeculationRules.php
+++ b/tests/phpunit/tests/speculative-loading/wpPrintSpeculationRules.php
@@ -43,7 +43,7 @@ public function test_wp_print_speculation_rules_with_html5_support() {
 
 		add_filter(
 			'wp_speculation_rules_configuration',
-			function () {
+			static function () {
 				return array(
 					'mode'      => 'prerender',
 					'eagerness' => 'moderate',
@@ -70,7 +70,7 @@ public function test_wp_print_speculation_rules_without_html5_support() {
 
 		add_filter(
 			'wp_speculation_rules_configuration',
-			function () {
+			static function () {
 				return array(
 					'mode'      => 'prerender',
 					'eagerness' => 'moderate',