diff --git a/src/Access/RelationshipFieldAccess.php b/src/Access/RelationshipFieldAccess.php
index 0be984c..f233dc9 100644
--- a/src/Access/RelationshipFieldAccess.php
+++ b/src/Access/RelationshipFieldAccess.php
@@ -52,7 +52,7 @@ class RelationshipFieldAccess implements AccessInterface {
         if ($access_result instanceof AccessResultReasonInterface) {
           $reason = "The current user is not allowed to {$field_operation} this relationship.";
           if ($access_reason = $access_result->getReason()) {
-            $reason .= $access_reason;
+            $reason .= " {$access_reason}";
           };
           $access_result->setReason($reason);
         }
diff --git a/tests/src/Functional/JsonApiFunctionalTest.php b/tests/src/Functional/JsonApiFunctionalTest.php
index cbdfa4c..35a8566 100644
--- a/tests/src/Functional/JsonApiFunctionalTest.php
+++ b/tests/src/Functional/JsonApiFunctionalTest.php
@@ -723,9 +723,8 @@ class JsonApiFunctionalTest extends JsonApiFunctionalTestBase {
         ],
       ],
     ];
-    $relationship_url = Url::fromRoute('jsonapi.node--article.relationship', [
+    $relationship_url = Url::fromRoute('jsonapi.node--article.field_tags.relationship', [
       'node' => $uuid,
-      'related' => 'field_tags',
     ]);
     $response = $this->request('POST', $relationship_url, [
       'body' => Json::encode($body),
diff --git a/tests/src/Functional/JsonApiRegressionTest.php b/tests/src/Functional/JsonApiRegressionTest.php
index 0408803..d8ad43b 100644
--- a/tests/src/Functional/JsonApiRegressionTest.php
+++ b/tests/src/Functional/JsonApiRegressionTest.php
@@ -157,7 +157,7 @@ class JsonApiRegressionTest extends JsonApiFunctionalTestBase {
 
     // Test.
     $user = $this->drupalCreateUser(['bypass node access']);
-    $url = Url::fromRoute('jsonapi.node--page.relationship', ['node' => $node->uuid(), 'related' => 'field_test']);
+    $url = Url::fromRoute('jsonapi.node--page.field_test.relationship', ['node' => $node->uuid()]);
     $request_options = [
       RequestOptions::HEADERS => [
         'Content-Type' => 'application/vnd.api+json',
diff --git a/tests/src/Kernel/Controller/EntityResourceTest.php b/tests/src/Kernel/Controller/EntityResourceTest.php
index 2363541..203a5fd 100644
--- a/tests/src/Kernel/Controller/EntityResourceTest.php
+++ b/tests/src/Kernel/Controller/EntityResourceTest.php
@@ -767,86 +767,6 @@ class EntityResourceTest extends JsonapiKernelTestBase {
     $this->assertEquals(204, $response->getStatusCode());
   }
 
-  /**
-   * @covers ::getRelated
-   */
-  public function testGetRelatedInternal() {
-    $internal_resource_type = new ResourceType('node', 'article', NULL, TRUE);
-    $resource = $this->buildEntityResource('node', 'article', [
-      'field_relationships' => [$internal_resource_type],
-    ]);
-
-    $this->setExpectedException(NotFoundHttpException::class);
-    $resource->getRelationship($this->node, 'field_relationships', new Request());
-  }
-
-  /**
-   * @covers ::getRelationship
-   */
-  public function testGetRelationshipInternal() {
-    $internal_resource_type = new ResourceType('node', 'article', NULL, TRUE);
-    $resource = $this->buildEntityResource('node', 'article', [
-      'field_relationships' => [$internal_resource_type],
-    ]);
-
-    $this->setExpectedException(NotFoundHttpException::class);
-    $resource->getRelationship($this->node, 'field_relationships', new Request());
-  }
-
-  /**
-   * @covers ::createRelationship
-   */
-  public function testCreateRelationshipInternal() {
-    $internal_resource_type = new ResourceType('node', 'article', NULL, TRUE);
-    $resource = $this->buildEntityResource('node', 'article', [
-      'field_relationships' => [$internal_resource_type],
-    ]);
-
-    Role::load(Role::ANONYMOUS_ID)->grantPermission('edit any article content')->save();
-
-    $field_type_manager = $this->container->get('plugin.manager.field.field_type');
-    $list = $field_type_manager->createFieldItemList($this->node, 'field_relationships');
-
-    $this->setExpectedException(NotFoundHttpException::class);
-    $resource->createRelationship($this->node, 'field_relationships', $list, new Request());
-  }
-
-  /**
-   * @covers ::patchRelationship
-   */
-  public function testPatchRelationshipInternal() {
-    $internal_resource_type = new ResourceType('node', 'article', NULL, TRUE);
-    $resource = $this->buildEntityResource('node', 'article', [
-      'field_relationships' => [$internal_resource_type],
-    ]);
-
-    Role::load(Role::ANONYMOUS_ID)->grantPermission('edit any article content')->save();
-
-    $field_type_manager = $this->container->get('plugin.manager.field.field_type');
-    $list = $field_type_manager->createFieldItemList($this->node, 'field_relationships');
-
-    $this->setExpectedException(NotFoundHttpException::class);
-    $resource->patchRelationship($this->node, 'field_relationships', $list, new Request());
-  }
-
-  /**
-   * @covers ::deleteRelationship
-   */
-  public function testDeleteRelationshipInternal() {
-    $internal_resource_type = new ResourceType('node', 'article', NULL, TRUE);
-    $resource = $this->buildEntityResource('node', 'article', [
-      'field_relationships' => [$internal_resource_type],
-    ]);
-
-    Role::load(Role::ANONYMOUS_ID)->grantPermission('edit any article content')->save();
-
-    $field_type_manager = $this->container->get('plugin.manager.field.field_type');
-    $list = $field_type_manager->createFieldItemList($this->node, 'field_relationships');
-
-    $this->setExpectedException(NotFoundHttpException::class);
-    $resource->deleteRelationship($this->node, 'field_relationships', $list, new Request());
-  }
-
   /**
    * Provides data for the testDeleteRelationship.
    *