diff --git a/composer.json b/composer.json
index 6ff133a..4890988 100644
--- a/composer.json
+++ b/composer.json
@@ -33,7 +33,7 @@
     "dealerdirect/phpcodesniffer-composer-installer": "^1.0",
     "phpcompatibility/phpcompatibility-wp": "*",
     "sebastian/phpcpd": "^3.0 || ^4.0 || ^6.0",
-    "yoast/phpunit-polyfills": "^3.0",
+    "yoast/phpunit-polyfills": "^4.0",
     "mf2/mf2": "^0.5.0",
     "sirbrillig/phpcs-variable-analysis": "^2.11",
     "wp-cli/wp-cli": "^2.11",