diff --git a/composer.json b/composer.json
index 4c564f5..17c881b 100644
--- a/composer.json
+++ b/composer.json
@@ -15,7 +15,8 @@
     "wp-coding-standards/wpcs": "^2",
     "dealerdirect/phpcodesniffer-composer-installer": "^0.7.0",
     "phpunit/phpunit": "^7",
-    "phpcompatibility/php-compatibility": "^9.3"
+    "phpcompatibility/php-compatibility": "^9.3",
+    "yoast/phpunit-polyfills": "^1.0"
   },
   "scripts": {
     "lint": "@phpcs",
diff --git a/composer.lock b/composer.lock
index b0333df..907f432 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "96f944ff852531c8295ad8a80cfdc381",
+    "content-hash": "2fb3eac834ce14dc32fade3c1f75cef3",
     "packages": [],
     "packages-dev": [
         {
@@ -4530,6 +4530,69 @@
                 "wiki": "https://github.com/WordPress/WordPress-Coding-Standards/wiki"
             },
             "time": "2020-05-13T23:57:56+00:00"
+        },
+        {
+            "name": "yoast/phpunit-polyfills",
+            "version": "1.0.1",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/Yoast/PHPUnit-Polyfills.git",
+                "reference": "f014fb21c2b0038fd329515d59025af42fb98715"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/Yoast/PHPUnit-Polyfills/zipball/f014fb21c2b0038fd329515d59025af42fb98715",
+                "reference": "f014fb21c2b0038fd329515d59025af42fb98715",
+                "shasum": ""
+            },
+            "require": {
+                "php": ">=5.4",
+                "phpunit/phpunit": "^4.8.36 || ^5.7.21 || ^6.0 || ^7.0 || ^8.0 || ^9.0"
+            },
+            "require-dev": {
+                "php-parallel-lint/php-console-highlighter": "^0.5",
+                "php-parallel-lint/php-parallel-lint": "^1.3.0",
+                "yoast/yoastcs": "^2.1.0"
+            },
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-main": "1.x-dev",
+                    "dev-develop": "1.x-dev"
+                }
+            },
+            "autoload": {
+                "files": [
+                    "phpunitpolyfills-autoload.php"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "BSD-3-Clause"
+            ],
+            "authors": [
+                {
+                    "name": "Team Yoast",
+                    "email": "support@yoast.com",
+                    "homepage": "https://yoast.com"
+                },
+                {
+                    "name": "Contributors",
+                    "homepage": "https://github.com/Yoast/PHPUnit-Polyfills/graphs/contributors"
+                }
+            ],
+            "description": "Set of polyfills for changed PHPUnit functionality to allow for creating PHPUnit cross-version compatible tests",
+            "homepage": "https://github.com/Yoast/PHPUnit-Polyfills",
+            "keywords": [
+                "phpunit",
+                "polyfill",
+                "testing"
+            ],
+            "support": {
+                "issues": "https://github.com/Yoast/PHPUnit-Polyfills/issues",
+                "source": "https://github.com/Yoast/PHPUnit-Polyfills"
+            },
+            "time": "2021-08-09T16:28:08+00:00"
         }
     ],
     "aliases": [],
@@ -4541,5 +4604,5 @@
     "prefer-lowest": false,
     "platform": [],
     "platform-dev": [],
-    "plugin-api-version": "2.0.0"
+    "plugin-api-version": "2.1.0"
 }
diff --git a/package-lock.json b/package-lock.json
index 01889dd..9d16e4b 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -733,9 +733,9 @@
       "dev": true
     },
     "path-parse": {
-      "version": "1.0.6",
-      "resolved": "https://registry.npmjs.org/path-parse/-/path-parse-1.0.6.tgz",
-      "integrity": "sha512-GSmOT2EbHrINBf9SR7CDELwlJ8AENk3Qn7OikK4nFYAu3Ote2+JYNVvkpAEQm3/TLNEJFD/xZJjzyxg3KBWOzw==",
+      "version": "1.0.7",
+      "resolved": "https://registry.npmjs.org/path-parse/-/path-parse-1.0.7.tgz",
+      "integrity": "sha512-LDJzPVEEEPR+y48z93A0Ed0yXb8pAByGWo/k5YYdYgpY2/2EsOsksJrq7lOHxryrVOn1ejG6oAp8ahvOIQD8sw==",
       "dev": true
     },
     "path-root": {
diff --git a/tests/phpunit/bootstrap.php b/tests/phpunit/bootstrap.php
index 55c9ce6..ead560b 100644
--- a/tests/phpunit/bootstrap.php
+++ b/tests/phpunit/bootstrap.php
@@ -5,6 +5,8 @@
 	$_tests_dir = '/tmp/wordpress-tests-lib';
 }
 
+define( 'WP_TESTS_PHPUNIT_POLYFILLS_PATH', __DIR__ . '/../../vendor/yoast/phpunit-polyfills/phpunitpolyfills-autoload.php' );
+
 require_once $_tests_dir . '/includes/functions.php';
 
 if ( getenv( 'WP_CORE_DIR' ) ) {