diff --git a/bootstrap.php b/bootstrap.php
index 3b92cf7..c3d83e1 100644
--- a/bootstrap.php
+++ b/bootstrap.php
@@ -12,3 +12,4 @@
 SetEnv::setConfigFilePath();
 
 Bootstrap::init(getenv('WP_VERSION'));
+Bootstrap::requireWordPressTestEnv();
diff --git a/src/Bootstrap.php b/src/Bootstrap.php
index dfa5fb4..7f7937e 100644
--- a/src/Bootstrap.php
+++ b/src/Bootstrap.php
@@ -384,7 +384,14 @@ public static function init(string $wp_version): void
         self::displayLine('Bye!', '👋');
 
         self::displaySeparator();
+    }
 
+    /**
+     * Require the WP test environment
+     *
+     * This enables us to use WordPress' built-in functions in our tests.
+     */
+    public static function requireWordPressTestEnv(): void {
         require FetchWP::extractDirPath() .
         'wordpress-develop-trunk/tests/phpunit/includes/functions.php';