diff --git a/core/modules/system/system.install b/core/modules/system/system.install
index b63b7040df..bcefec57e1 100644
--- a/core/modules/system/system.install
+++ b/core/modules/system/system.install
@@ -316,17 +316,21 @@ function system_requirements($phase) {
 
   if ($phase == 'runtime' && PHP_SAPI != 'cli') {
     // Test the session configuration.
+    $cookie = ini_get('session.cookie_samesite');
     $requirements['php_session'] = [
       'title' => t('Session'),
-      'value' => t('SameSite cookie attribute: %samesite', ['%samesite' => ini_get('session.cookie_samesite')]),
+      'description' => t('This attribute should be explicitly set to Lax or Strict. See <a href="https://www.php.net/manual/en/session.configuration.php#ini.session.cookie-samesite" target="_blank">PHP documentation</a>'),
     ];
-    if (in_array(ini_get('session.cookie_samesite'), ['Lax', 'Strict'])) {
+    if (in_array($cookie, ['Lax', 'Strict'])) {
       $requirements['php_session']['severity'] = REQUIREMENT_OK;
     }
     else {
+      $cookie = t('invalid');
       $requirements['php_session']['severity'] = REQUIREMENT_WARNING;
-      $requirements['php_session']['description'] = '@todo';
     }
+    $requirements['php_session']['value'] = t('SameSite cookie attribute: %samesite', [
+      '%samesite' => $cookie,
+    ]);
   }
 
   // Test for PHP extensions.