diff --git a/core/modules/system/lib/Drupal/system/Tests/Session/SessionHttpsTest.php b/core/modules/system/lib/Drupal/system/Tests/Session/SessionHttpsTest.php
index c1e54dd..b338b7b 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Session/SessionHttpsTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Session/SessionHttpsTest.php
@@ -246,6 +246,7 @@ protected function assertSessionIds($sid, $ssid, $assertion_text) {
    */
   protected function httpsUrl($url) {
     global $base_url;
+    $this->request->server->set('HTTPS', 'on');
     return $base_url . '/core/modules/system/tests/https.php/' . $url;
   }