diff --git a/src/Context/FieldResolver.php b/src/Context/FieldResolver.php
index edeea5b..de2cb3b 100644
--- a/src/Context/FieldResolver.php
+++ b/src/Context/FieldResolver.php
@@ -56,7 +56,7 @@ class FieldResolver {
    * Example:
    *   'field_author.entity.field_first_name' -> 'author.firstName'.
    *
-   * @param string $field_name
+   * @param string $internal_field_name
    *   The Drupal field name to map to a public field name.
    *
    * @return string
diff --git a/src/Controller/EntityResource.php b/src/Controller/EntityResource.php
index 3536e6c..a3c3b43 100644
--- a/src/Controller/EntityResource.php
+++ b/src/Controller/EntityResource.php
@@ -614,6 +614,7 @@ class EntityResource {
     else {
       $pagination = new OffsetPage(OffsetPage::DEFAULT_OFFSET, OffsetPage::SIZE_MAX);
     }
+    // Add one extra element to the page to see if there are more pages needed.
     $query->range($pagination->offset(), $pagination->size() + 1);
     $query->addMetaData('pager_size', (int) $pagination->size());
 
diff --git a/src/Query/EntityCondition.php b/src/Query/EntityCondition.php
index d1c2672..88e59a4 100644
--- a/src/Query/EntityCondition.php
+++ b/src/Query/EntityCondition.php
@@ -2,6 +2,11 @@
 
 namespace Drupal\jsonapi\Query;
 
+/**
+ * A condition object for the EntityQuery.
+ *
+ * @internal
+ */
 class EntityCondition {
 
   /**
diff --git a/src/Query/EntityConditionGroup.php b/src/Query/EntityConditionGroup.php
index 2723565..e7a2db2 100644
--- a/src/Query/EntityConditionGroup.php
+++ b/src/Query/EntityConditionGroup.php
@@ -2,6 +2,11 @@
 
 namespace Drupal\jsonapi\Query;
 
+/**
+ * A condition group for the EntityQuery.
+ *
+ * @internal
+ */
 class EntityConditionGroup {
 
   /**
diff --git a/src/Query/Filter.php b/src/Query/Filter.php
index 78880f6..925862e 100644
--- a/src/Query/Filter.php
+++ b/src/Query/Filter.php
@@ -6,6 +6,11 @@ use Drupal\Core\Entity\Query\QueryInterface;
 use Drupal\jsonapi\Query\EntityCondition;
 use Drupal\jsonapi\Query\EntityConditionGroup;
 
+/**
+ * Gathers information about the filter parameter.
+ *
+ * @internal
+ */
 class Filter {
 
   /**
diff --git a/src/Query/Sort.php b/src/Query/Sort.php
index da8dd9d..14f9c0d 100644
--- a/src/Query/Sort.php
+++ b/src/Query/Sort.php
@@ -2,6 +2,11 @@
 
 namespace Drupal\jsonapi\Query;
 
+/**
+ * Gathers information about the sort parameter.
+ *
+ * @internal
+ */
 class Sort {
 
   /**
diff --git a/tests/src/Kernel/Context/FieldResolverTest.php b/tests/src/Kernel/Context/FieldResolverTest.php
index 932c1aa..30a04a5 100644
--- a/tests/src/Kernel/Context/FieldResolverTest.php
+++ b/tests/src/Kernel/Context/FieldResolverTest.php
@@ -171,10 +171,9 @@ class FieldResolverTest extends JsonapiKernelTestBase {
    * Expects an error when an invalid field is provided.
    *
    * @covers ::resolveInternal
-   *
-   * @expectedException \Symfony\Component\HttpKernel\Exception\BadRequestHttpException
    */
   public function testResolveInternalError() {
+    $this->expectException(BadRequestHttpException::class);
     $original = 'host.fail!!.deep';
     $not_expected = 'host.entity.fail!!.entity.deep';
 
diff --git a/tests/src/Unit/LinkManager/LinkManagerTest.php b/tests/src/Unit/LinkManager/LinkManagerTest.php
index a9503a9..2a43b52 100644
--- a/tests/src/Unit/LinkManager/LinkManagerTest.php
+++ b/tests/src/Unit/LinkManager/LinkManagerTest.php
@@ -11,6 +11,7 @@ use Symfony\Cmf\Component\Routing\ChainRouterInterface;
 use Symfony\Cmf\Component\Routing\RouteObjectInterface;
 use Symfony\Component\HttpFoundation\ParameterBag;
 use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpKernel\Exception\BadRequestHttpException;
 
 /**
  * @coversDefaultClass \Drupal\jsonapi\LinkManager\LinkManager
@@ -134,10 +135,10 @@ class LinkManagerTest extends UnitTestCase {
    * Test errors.
    *
    * @covers ::getPagerLinks
-   * @expectedException \Symfony\Component\HttpKernel\Exception\BadRequestHttpException
    * @dataProvider getPagerLinksErrorProvider
    */
   public function testGetPagerLinksError($offset, $size, $has_next_page, $total, $include_count, array $pages) {
+    $this->expectException(BadRequestHttpException::class);
     $this->testGetPagerLinks($offset, $size, $has_next_page, $total, $include_count, $pages);
   }