tests/src/Functional/ResourceTestBase.php | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/tests/src/Functional/ResourceTestBase.php b/tests/src/Functional/ResourceTestBase.php
index 49efa5c..ab47175 100644
--- a/tests/src/Functional/ResourceTestBase.php
+++ b/tests/src/Functional/ResourceTestBase.php
@@ -865,7 +865,7 @@ abstract class ResourceTestBase extends BrowserTestBase {
         ],
       ],
     ];
-    $this->assertResourceResponse(422, json_encode($expected), $response);
+    $this->assertResourceResponse(422, Json::encode($expected), $response);
     /* $this->assertResourceErrorResponse(422, "$label_field: $label_field_capitalized: this field cannot hold more than 1 values.", $response, '/data/attributes/' . $label_field); */
 
     $request_options[RequestOptions::BODY] = $parseable_invalid_request_body_2;
@@ -1062,7 +1062,7 @@ abstract class ResourceTestBase extends BrowserTestBase {
         ],
       ],
     ];
-    $this->assertResourceResponse(422, json_encode($expected), $response);
+    $this->assertResourceResponse(422, Json::encode($expected), $response);
     /* $this->assertResourceErrorResponse(422, "$label_field: $label_field_capitalized: this field cannot hold more than 1 values.", $response, '/data/attributes/' . $label_field); */
 
     $request_options[RequestOptions::BODY] = $parseable_invalid_request_body_2;
@@ -1157,7 +1157,7 @@ abstract class ResourceTestBase extends BrowserTestBase {
     foreach (array_keys(static::$patchProtectedFieldNames) as $field_name) {
       unset($valid_request_body['data']['attributes'][$field_name]);
     }
-    $request_options[RequestOptions::BODY] = json_encode($valid_request_body);
+    $request_options[RequestOptions::BODY] = Json::encode($valid_request_body);
     $response = $this->request('PATCH', $url, $request_options);
     // @todo investigate this more (cache tags + contexts), cfr https://www.drupal.org/project/drupal/issues/2626298 + https://www.drupal.org/project/jsonapi/issues/2933939
     $this->assertResourceResponse(200, FALSE, $response, Cache::mergeTags(['http_response', $this->entity->getCacheTags()[0]], []), $this->getExpectedCacheContexts());