diff --git a/core/modules/jsonapi/tests/src/Functional/JsonApiFunctionalTest.php b/core/modules/jsonapi/tests/src/Functional/JsonApiFunctionalTest.php
index 9f012309e5acbc1e0593f6ee62de6deea589ffb6..272fbdf395c44c073af44b6c21b1292547ac1748 100644
--- a/core/modules/jsonapi/tests/src/Functional/JsonApiFunctionalTest.php
+++ b/core/modules/jsonapi/tests/src/Functional/JsonApiFunctionalTest.php
@@ -660,7 +660,7 @@ public function testWrite() {
     $created_response = Json::decode($response->getBody()->__toString());
     $this->assertEquals(422, $response->getStatusCode());
     $this->assertNotEmpty($created_response['errors']);
-    $this->assertEquals('Unprocessable Entity', $created_response['errors'][0]['title']);
+    $this->assertStringStartsWith('Unprocessable', $created_response['errors'][0]['title']);
     // 6.2 Relationships are not included in "data".
     $malformed_body = $body;
     unset($malformed_body['data']['relationships']);
@@ -849,7 +849,7 @@ public function testWrite() {
     $this->assertEquals(422, $response->getStatusCode());
     $this->assertCount(2, $updated_response['errors']);
     for ($i = 0; $i < 2; $i++) {
-      $this->assertEquals("Unprocessable Entity", $updated_response['errors'][$i]['title']);
+      $this->assertStringStartsWith('Unprocessable', $updated_response['errors'][$i]['title']);
       $this->assertEquals(422, $updated_response['errors'][$i]['status']);
     }
     $this->assertEquals("title: This value should not be null.", $updated_response['errors'][0]['detail']);