diff --git a/core/modules/image/tests/src/Functional/QuickEditImageControllerTest.php b/core/modules/image/tests/src/Functional/QuickEditImageControllerTest.php
index c598b0e293..b3ed60c3c1 100644
--- a/core/modules/image/tests/src/Functional/QuickEditImageControllerTest.php
+++ b/core/modules/image/tests/src/Functional/QuickEditImageControllerTest.php
@@ -128,11 +128,8 @@ public function testValidImageUpload() {
     $this->assertTrue($valid_image);
 
     $this->drupalLogin($this->contentAuthorUser);
-    $response = $this->uploadImage($valid_image, $node->id(), $this->fieldName, $node->language()->getId());
-
-    $this->assertEqual($response->getStatusCode(), 200);
-    $this->assertEqual($response->getReasonPhrase(), 'OK');
-    $this->assertContains('"fid":"1"', $response->getBody()->getContents(), t('Valid upload completed successfully.'));
+    $this->uploadImage($valid_image, $node->id(), $this->fieldName, $node->language()->getId());
+    $this->assertContains('"fid":"1"', $this->getSession()->getPage()->getContent(), 'Valid upload completed successfully.');
   }
 
   /**
@@ -160,11 +157,8 @@ public function testInvalidUpload() {
     $this->assertTrue($invalid_image);
 
     $this->drupalLogin($this->contentAuthorUser);
-    $response = $this->uploadImage($invalid_image, $node->id(), $this->fieldName, $node->language()->getId());
-
-    $this->assertEqual($response->getStatusCode(), 200);
-    $this->assertEqual($response->getReasonPhrase(), 'OK');
-    $this->assertContains('"main_error":"The image failed validation."', $response->getBody()->getContents(), t('Invalid upload returned errors.'));
+    $this->uploadImage($invalid_image, $node->id(), $this->fieldName, $node->language()->getId());
+    $this->assertContains('"main_error":"The image failed validation."', $this->getSession()->getPage()->getContent(), 'Invalid upload returned errors.');
   }
 
   /**
@@ -178,43 +172,14 @@ public function testInvalidUpload() {
    *   The target field machine name.
    * @param string $langcode
    *   The langcode to use when setting the field's value.
-   *
-   * @return \Psr\Http\Message\ResponseInterface
-   *   The request response.
    */
   public function uploadImage($image, $nid, $field_name, $langcode) {
     $filepath = $this->container->get('file_system')->realpath($image->uri);
     $path = 'quickedit/image/upload/node/' . $nid . '/' . $field_name . '/' . $langcode . '/default';
 
-    // We assemble the curl request ourselves as drupalPost cannot process file
-    // uploads, and drupalPostForm only works with typical Drupal forms.
-    $client = $this->getHttpClient();
-    // Perform HTTP request.
-    return $client->post($this->buildUrl($path, []), [
-      'multipart' => [
-        [
-          'name'     => 'files[image]',
-          'contents' => fopen($filepath, 'r')
-        ]
-      ],
-      'http_errors' => FALSE,
-      'cookies'     => $this->cookies,
-    ]);
-  }
-
-  /**
-   * Obtain the HTTP client and set the cookies.
-   *
-   * @return \GuzzleHttp\Client
-   *   The client with BrowserTestBase configuration.
-   */
-  protected function getHttpClient() {
-    // Similar code is also employed to test CSRF tokens.
-    // @see \Drupal\Tests\system\Functional\CsrfRequestHeaderTest::testRouteAccess()
-    $domain = parse_url($this->getUrl(), PHP_URL_HOST);
-    $session_id = $this->getSession()->getCookie($this->getSessionName());
-    $this->cookies = CookieJar::fromArray([$this->getSessionName() => $session_id], $domain);
-    return $this->getSession()->getDriver()->getClient()->getClient();
+    $this->prepareRequest();
+    $client = $this->getSession()->getDriver()->getClient();
+    $client->request('POST', $this->buildUrl($path, []), [], ['files[image]' => $filepath]);
   }
 
 }