diff --git a/core/modules/field/tests/src/Functional/EntityReference/Views/SelectionTest.php b/core/modules/field/tests/src/Functional/EntityReference/Views/SelectionTest.php
index 584cf4e..eadf740 100644
--- a/core/modules/field/tests/src/Functional/EntityReference/Views/SelectionTest.php
+++ b/core/modules/field/tests/src/Functional/EntityReference/Views/SelectionTest.php
@@ -2,6 +2,7 @@
 
 namespace Drupal\Tests\field\Functional\EntityReference\Views;
 
+use Drupal\Component\Serialization\Json;
 use Drupal\Component\Utility\Crypt;
 use Drupal\Core\Site\Settings;
 use Drupal\field\Entity\FieldConfig;
@@ -105,7 +106,7 @@ public function testAutocompleteOutput() {
     $selection_settings_key = Crypt::hmacBase64(serialize($selection_settings) . $target_type . $selection_handler, Settings::getHashSalt());
     \Drupal::keyValue('entity_autocomplete')->set($selection_settings_key, $selection_settings);
 
-    $result = $this->drupalGetJSON('entity_reference_autocomplete/' . $target_type . '/' . $selection_handler . '/' . $selection_settings_key, ['query' => ['q' => 't']]);
+    $result = Json::decode($this->drupalGet('entity_reference_autocomplete/' . $target_type . '/' . $selection_handler . '/' . $selection_settings_key, ['query' => ['q' => 't']]));
 
     $expected = [
       0 => [