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 6f82cb4..a0c628f 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Session/SessionHttpsTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Session/SessionHttpsTest.php
@@ -158,7 +158,7 @@ protected function testHttpsSession() {
 
     // Now try with a secure URL and make sure the submission succeeds.
     $form[0]['action'] = $this->httpsUrl('user');
-    $this->drupalPost(NULL, $edit, t('Log in'));
+    $this->drupalPostForm(NULL, $edit, t('Log in'));
     $this->assertNoText(t('This form must be submitted over a secure connection.'), 'Form submission succeeded over HTTPS.');
     $this->assertLink(t('Log out'), 0, t('User %name successfully logged in.', array('%name' => $user->name)));