diff --git a/core/modules/menu_ui/tests/src/Functional/MenuTest.php b/core/modules/menu_ui/tests/src/Functional/MenuTest.php
index 308eb67b69..c40e4710d2 100644
--- a/core/modules/menu_ui/tests/src/Functional/MenuTest.php
+++ b/core/modules/menu_ui/tests/src/Functional/MenuTest.php
@@ -578,9 +578,16 @@ public function testBlockContextualLinks() {
     // Get server-rendered contextual links.
     // @see \Drupal\contextual\Tests\ContextualDynamicContextTest:renderContextualLinks()
     $post = ['ids[0]' => $id];
-    $response = $this->drupalPost('contextual/render', 'application/json', $post, ['query' => ['destination' => 'test-page']]);
-    $this->assertResponse(200);
-    $json = Json::decode($response);
+    $client = \Drupal::httpClient();
+    $url = $this->buildUrl('contextual/render', ['query' => ['destination' => 'test-page']]);
+    $response = $client->post($url, [
+      'form_params' => $post,
+      'headers' => [
+        'Accept' => 'application/json',
+      ],
+    ]);
+    $this->assertEquals(200, $response->getStatusCode());
+    $json = Json::decode((string) $response);
     $this->assertIdentical($json[$id], '<ul class="contextual-links"><li class="block-configure"><a href="' . base_path() . 'admin/structure/block/manage/' . $block->id() . '">Configure block</a></li><li class="entitymenuedit-form"><a href="' . base_path() . 'admin/structure/menu/manage/' . $custom_menu->id() . '">Edit menu</a></li></ul>');
   }