diff --git a/src/Controller/EntityResource.php b/src/Controller/EntityResource.php
index aed2498..740c64e 100644
--- a/src/Controller/EntityResource.php
+++ b/src/Controller/EntityResource.php
@@ -38,7 +38,6 @@ use Drupal\jsonapi\ResourceResponse;
 use Drupal\jsonapi\ResourceType\ResourceType;
 use Drupal\jsonapi\ResourceType\ResourceTypeRepositoryInterface;
 use Drupal\jsonapi\Revisions\ResourceVersionRouteEnhancer;
-use Drupal\jsonapi\Routing\Routes;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpKernel\Exception\BadRequestHttpException;
 use Drupal\Core\Http\Exception\CacheableBadRequestHttpException;
@@ -155,11 +154,11 @@ class EntityResource {
    *   Thrown when access to the entity is not allowed.
    */
   public function getIndividual(EntityInterface $entity, Request $request) {
-    $entity = $this->entityAccessChecker->getAccessCheckedResourceObject($entity);
-    if ($entity instanceof EntityAccessDeniedHttpException) {
-      throw $entity;
+    $resource_object = $this->entityAccessChecker->getAccessCheckedResourceObject($entity);
+    if ($resource_object instanceof EntityAccessDeniedHttpException) {
+      throw $resource_object;
     }
-    $response = $this->buildWrappedResponse($entity, $request, $this->getIncludes($request, $entity));
+    $response = $this->buildWrappedResponse($resource_object, $request, $this->getIncludes($request, $resource_object));
     return $response;
   }
 
@@ -216,7 +215,8 @@ class EntityResource {
     $parsed_entity->save();
 
     // Build response object.
-    $response = $this->buildWrappedResponse(new ResourceObject($resource_type, $parsed_entity), $request, $this->getIncludes($request, $parsed_entity), 201);
+    $resource_object = new ResourceObject($resource_type, $parsed_entity);
+    $response = $this->buildWrappedResponse($resource_object, $request, $this->getIncludes($request, $resource_object), 201);
 
     // According to JSON:API specification, when a new entity was created
     // we should send "Location" header to the frontend.
@@ -274,7 +274,8 @@ class EntityResource {
 
     static::validate($entity, $field_names);
     $entity->save();
-    return $this->buildWrappedResponse(new ResourceObject($resource_type, $entity), $request, $this->getIncludes($request, $entity));
+    $resource_object = new ResourceObject($resource_type, $entity);
+    return $this->buildWrappedResponse($resource_object, $request, $this->getIncludes($request, $resource_object));
   }
 
   /**
@@ -449,7 +450,7 @@ class EntityResource {
       $collection_data[] = $this->entityAccessChecker->getAccessCheckedResourceObject($referenced_entity);
     }
     $entity_collection = new EntityCollection($collection_data, $field_list->getFieldDefinition()->getFieldStorageDefinition()->getCardinality());
-    $response = $this->buildWrappedResponse($entity_collection, $request, $this->getIncludes($request, $entity_collection, $related));
+    $response = $this->buildWrappedResponse($entity_collection, $request, $this->getIncludes($request, $entity_collection));
 
     // $response does not contain the entity list cache tag. We add the
     // cacheable metadata for the finite list of entities in the relationship.
@@ -937,9 +938,6 @@ class EntityResource {
    *   The request object.
    * @param \Drupal\Core\Entity\EntityInterface|\Drupal\jsonapi\JsonApiResource\EntityCollection $data
    *   The response data from which to resolve includes.
-   * @param string $related
-   *   (optional) The relationship field name to be given for getting includes
-   *   on a related route.
    *
    * @return \Drupal\jsonapi\JsonApiResource\EntityCollection
    *   An EntityCollection to be included or a NullEntityCollection if the
@@ -948,9 +946,9 @@ class EntityResource {
    * @throws \Drupal\Component\Plugin\Exception\InvalidPluginDefinitionException
    * @throws \Drupal\Component\Plugin\Exception\PluginNotFoundException
    */
-  public function getIncludes(Request $request, $data, $related = NULL) {
+  public function getIncludes(Request $request, $data) {
     return $request->query->has('include') && ($include_parameter = $request->query->get('include')) && !empty($include_parameter)
-      ? $this->includeResolver->resolve($request->get(Routes::RESOURCE_TYPE_KEY), $data, $include_parameter, $related)
+      ? $this->includeResolver->resolve($data, $include_parameter)
       : new NullEntityCollection();
   }
 
diff --git a/src/IncludeResolver.php b/src/IncludeResolver.php
index 065295a..3104026 100644
--- a/src/IncludeResolver.php
+++ b/src/IncludeResolver.php
@@ -47,8 +47,6 @@ class IncludeResolver {
   /**
    * Resolves included resources.
    *
-   * @param \Drupal\jsonapi\ResourceType\ResourceType $base_resource_type
-   *   The base resource type for which includes are to be resolved.
    * @param \Drupal\jsonapi\JsonApiResource\ResourceIdentifierInterface|\Drupal\jsonapi\JsonApiResource\EntityCollection $data
    *   The resource(s) for which to resolve includes.
    * @param string $include_parameter
@@ -64,11 +62,11 @@ class IncludeResolver {
    * @throws \Drupal\Component\Plugin\Exception\InvalidPluginDefinitionException
    *   Thrown if a storage handler couldn't be loaded.
    */
-  public function resolve(ResourceType $base_resource_type, $data, $include_parameter, $related_field = NULL) {
+  public function resolve($data, $include_parameter, $related_field = NULL) {
     assert($data instanceof ResourceIdentifierInterface || $data instanceof EntityCollection);
     // Map a single entity into an EntityCollection.
     $entity_collection = $data instanceof ResourceIdentifierInterface ? new EntityCollection([$data], 1) : $data;
-    $include_tree = static::toIncludeTree($base_resource_type, $include_parameter, $related_field);
+    $include_tree = static::toIncludeTree($entity_collection, $include_parameter);
     return EntityCollection::deduplicate($this->resolveIncludeTree($include_tree, $entity_collection));
   }
 
@@ -161,26 +159,27 @@ class IncludeResolver {
   /**
    * Returns a tree of field names to include from an include parameter.
    *
-   * @param \Drupal\jsonapi\ResourceType\ResourceType $base_resource_type
-   *   The base resource type from which to resolve an internal include path.
+   * @param \Drupal\jsonapi\JsonApiResource\EntityCollection $entity_collection
+   *   The base resources for which includes should be resolved.
    * @param string $include_parameter
    *   The raw include parameter value.
-   * @param string|null $related_field
-   *   A relationship field name if the includes are being resolved on a
-   *   relationship route.
    *
    * @return array
    *   An multi-dimensional array representing a tree of field names to be
    *   included. Array keys are the field names. Leaves are empty arrays.
    */
-  protected static function toIncludeTree(ResourceType $base_resource_type, $include_parameter, $related_field) {
+  protected static function toIncludeTree(EntityCollection $entity_collection, $include_parameter) {
     // $include_parameter: 'one.two.three, one.two.four'.
     $include_paths = array_map('trim', explode(',', $include_parameter));
     // $exploded_paths: [['one', 'two', 'three'], ['one', 'two', 'four']].
     $exploded_paths = array_map(function ($include_path) {
       return array_map('trim', explode('.', $include_path));
     }, $include_paths);
-    $resolved_paths = static::resolveInternalIncludePaths($base_resource_type, $exploded_paths, $related_field);
+    $resolved_paths = [];
+    /* @var \Drupal\jsonapi\JsonApiResource\ResourceIdentifierInterface $item */
+    foreach ($entity_collection as $item) {
+      $resolved_paths = array_merge($resolved_paths, static::resolveInternalIncludePaths($item->getResourceType(), $exploded_paths));
+    }
     return static::buildTree($resolved_paths);
   }
 
@@ -191,9 +190,6 @@ class IncludeResolver {
    *   The base resource type from which to resolve an internal include path.
    * @param array $paths
    *   An array of exploded include paths.
-   * @param string|null $related_field
-   *   A relationship field name if the includes are being resolved on a
-   *   relationship route.
    *
    * @return array
    *   An array of all possible internal include paths derived from the given
@@ -201,17 +197,12 @@ class IncludeResolver {
    *
    * @see self::buildTree
    */
-  protected static function resolveInternalIncludePaths(ResourceType $base_resource_type, array $paths, $related_field) {
-    $internal_paths = array_map(function ($exploded_path) use ($base_resource_type, $related_field) {
+  protected static function resolveInternalIncludePaths(ResourceType $base_resource_type, array $paths) {
+    $internal_paths = array_map(function ($exploded_path) use ($base_resource_type) {
       if (empty($exploded_path)) {
         return [];
       }
-      $resolved_paths = FieldResolver::resolveInternalIncludePath($base_resource_type, $related_field ? array_merge([$related_field], $exploded_path) : $exploded_path);
-      return $related_field
-        ? array_map(function ($resolved_path) {
-          return array_slice($resolved_path, 1);
-        }, $resolved_paths)
-        : $resolved_paths;
+      return FieldResolver::resolveInternalIncludePath($base_resource_type, $exploded_path);
     }, $paths);
     $flattened_paths = array_reduce($internal_paths, 'array_merge', []);
     return $flattened_paths;
diff --git a/tests/src/Kernel/Normalizer/JsonApiDocumentTopLevelNormalizerTest.php b/tests/src/Kernel/Normalizer/JsonApiDocumentTopLevelNormalizerTest.php
index dec157e..ec86b67 100644
--- a/tests/src/Kernel/Normalizer/JsonApiDocumentTopLevelNormalizerTest.php
+++ b/tests/src/Kernel/Normalizer/JsonApiDocumentTopLevelNormalizerTest.php
@@ -218,7 +218,7 @@ class JsonApiDocumentTopLevelNormalizerTest extends JsonapiKernelTestBase {
     list($request, $resource_type) = $this->generateProphecies('node', 'article');
 
     $resource_object = new ResourceObject($resource_type, $this->node);
-    $includes = $this->includeResolver->resolve($resource_type, $resource_object, 'uid,field_tags,field_image');
+    $includes = $this->includeResolver->resolve($resource_object, 'uid,field_tags,field_image');
 
     $jsonapi_doc_object = $this
       ->getNormalizer()
@@ -349,7 +349,7 @@ class JsonApiDocumentTopLevelNormalizerTest extends JsonapiKernelTestBase {
     list($request, $resource_type) = $this->generateProphecies('node', 'article', 'uuid');
     $resource_object = new ResourceObject($resource_type, $this->node);
     $include_param = 'uid,field_tags';
-    $includes = $this->includeResolver->resolve($resource_type, $resource_object, $include_param);
+    $includes = $this->includeResolver->resolve($resource_object, $include_param);
     $document_wrapper = new JsonApiDocumentTopLevel($resource_object, $includes, new LinkCollection([]));
 
     $request->query = new ParameterBag([