diff --git a/core/lib/Drupal/Core/Entity/ContentEntityDeleteFormBase.php b/core/lib/Drupal/Core/Entity/ContentEntityDeleteFormBase.php
index 21e5898..794b792 100644
--- a/core/lib/Drupal/Core/Entity/ContentEntityDeleteFormBase.php
+++ b/core/lib/Drupal/Core/Entity/ContentEntityDeleteFormBase.php
@@ -17,7 +17,7 @@
   /**
    * {@inheritdoc}
    */
-  public function save(array $form, FormStateInterface &$form_state) {
+  public function save(array $form, FormStateInterface $form_state) {
     $this->entity->delete();
   }
 
diff --git a/core/lib/Drupal/Core/Entity/EntityDeleteFormBase.php b/core/lib/Drupal/Core/Entity/EntityDeleteFormBase.php
index 5ec14b9..0789a25 100644
--- a/core/lib/Drupal/Core/Entity/EntityDeleteFormBase.php
+++ b/core/lib/Drupal/Core/Entity/EntityDeleteFormBase.php
@@ -19,7 +19,7 @@
   /**
    * {@inheritdoc}
    */
-  public function save(array $form, FormStateInterface &$form_state) {
+  public function save(array $form, FormStateInterface $form_state) {
     $this->entity->delete();
   }
 
diff --git a/core/modules/block/src/BlockForm.php b/core/modules/block/src/BlockForm.php
index ade344f..d6eb8bb 100644
--- a/core/modules/block/src/BlockForm.php
+++ b/core/modules/block/src/BlockForm.php
@@ -181,7 +181,7 @@ public function submit(array $form, FormStateInterface $form_state) {
   /**
    * {@inheritdoc}
    */
-  public function save(array $form, FormStateInterface &$form_state) {
+  public function save(array $form, FormStateInterface $form_state) {
     parent::save($form, $form_state);
 
     drupal_set_message($this->t('The block configuration has been saved.'));
diff --git a/core/modules/block_content/src/Form/BlockContentAddForm.php b/core/modules/block_content/src/Form/BlockContentAddForm.php
index 71780d1..e966262 100644
--- a/core/modules/block_content/src/Form/BlockContentAddForm.php
+++ b/core/modules/block_content/src/Form/BlockContentAddForm.php
@@ -17,7 +17,7 @@ class BlockContentAddForm extends BlockContentFormBase {
   /**
    * {@inheritdoc}
    */
-  public function save(array $form, FormStateInterface &$form_state) {
+  public function save(array $form, FormStateInterface $form_state) {
     parent::save($form, $form_state);
 
     $block = $this->entity;
diff --git a/core/modules/block_content/src/Form/BlockContentEditForm.php b/core/modules/block_content/src/Form/BlockContentEditForm.php
index 8596c93..7b47542 100644
--- a/core/modules/block_content/src/Form/BlockContentEditForm.php
+++ b/core/modules/block_content/src/Form/BlockContentEditForm.php
@@ -17,7 +17,7 @@ class BlockContentEditForm extends BlockContentFormBase {
   /**
    * {@inheritdoc}
    */
-  public function save(array $form, FormStateInterface &$form_state) {
+  public function save(array $form, FormStateInterface $form_state) {
     parent::save($form, $form_state);
 
     $block = $this->entity;
diff --git a/core/modules/block_content/src/Form/BlockContentTypeAddForm.php b/core/modules/block_content/src/Form/BlockContentTypeAddForm.php
index dc1428d..ae9aac7 100644
--- a/core/modules/block_content/src/Form/BlockContentTypeAddForm.php
+++ b/core/modules/block_content/src/Form/BlockContentTypeAddForm.php
@@ -17,7 +17,7 @@ class BlockContentTypeAddForm extends BlockContentTypeFormBase {
   /**
    * {@inheritdoc}
    */
-  public function save(array $form, FormStateInterface &$form_state) {
+  public function save(array $form, FormStateInterface $form_state) {
     parent::save($form, $form_state);
 
     $block_type = $this->entity;
diff --git a/core/modules/block_content/src/Form/BlockContentTypeEditForm.php b/core/modules/block_content/src/Form/BlockContentTypeEditForm.php
index 3fb4304..922c3d7 100644
--- a/core/modules/block_content/src/Form/BlockContentTypeEditForm.php
+++ b/core/modules/block_content/src/Form/BlockContentTypeEditForm.php
@@ -17,7 +17,7 @@ class BlockContentTypeEditForm extends BlockContentTypeFormBase {
   /**
    * {@inheritdoc}
    */
-  public function save(array $form, FormStateInterface &$form_state) {
+  public function save(array $form, FormStateInterface $form_state) {
     parent::save($form, $form_state);
 
     $block_type = $this->entity;
diff --git a/core/modules/block_content/src/Form/BlockContentTypeFormBase.php b/core/modules/block_content/src/Form/BlockContentTypeFormBase.php
index 8e31856..f218d87 100644
--- a/core/modules/block_content/src/Form/BlockContentTypeFormBase.php
+++ b/core/modules/block_content/src/Form/BlockContentTypeFormBase.php
@@ -88,7 +88,7 @@ public function form(array $form, FormStateInterface $form_state) {
   /**
    * Overrides \Drupal\Core\Entity\EntityForm::save().
    */
-  public function save(array $form, FormStateInterface &$form_state) {
+  public function save(array $form, FormStateInterface $form_state) {
     parent::save($form, $form_state);
 
     $form_state->setRedirect('block_content.type_list');
diff --git a/core/modules/comment/src/Form/CommentTypeAddForm.php b/core/modules/comment/src/Form/CommentTypeAddForm.php
index 66ce52a..d35ca21 100644
--- a/core/modules/comment/src/Form/CommentTypeAddForm.php
+++ b/core/modules/comment/src/Form/CommentTypeAddForm.php
@@ -17,7 +17,7 @@ class CommentTypeAddForm extends CommentTypeFormBase {
   /**
    * {@inheritdoc}
    */
-  public function save(array $form, FormStateInterface &$form_state) {
+  public function save(array $form, FormStateInterface $form_state) {
     parent::save($form, $form_state);
 
     $block_type = $this->entity;
diff --git a/core/modules/comment/src/Form/CommentTypeEditForm.php b/core/modules/comment/src/Form/CommentTypeEditForm.php
index dd901a6..fcf9470 100644
--- a/core/modules/comment/src/Form/CommentTypeEditForm.php
+++ b/core/modules/comment/src/Form/CommentTypeEditForm.php
@@ -17,7 +17,7 @@ class CommentTypeEditForm extends CommentTypeFormBase {
   /**
    * {@inheritdoc}
    */
-  public function save(array $form, FormStateInterface &$form_state) {
+  public function save(array $form, FormStateInterface $form_state) {
     parent::save($form, $form_state);
 
     $block_type = $this->entity;
diff --git a/core/modules/comment/src/Form/CommentTypeFormBase.php b/core/modules/comment/src/Form/CommentTypeFormBase.php
index 1ef62a9..74912ad 100644
--- a/core/modules/comment/src/Form/CommentTypeFormBase.php
+++ b/core/modules/comment/src/Form/CommentTypeFormBase.php
@@ -133,7 +133,7 @@ public function form(array $form, FormStateInterface $form_state) {
   /**
    * {@inheritdoc}
    */
-  public function save(array $form, FormStateInterface &$form_state) {
+  public function save(array $form, FormStateInterface $form_state) {
     parent::save($form, $form_state);
 
     $form_state->setRedirect('comment.type_list');
diff --git a/core/modules/config/tests/config_test/src/Form/ConfigTestAddForm.php b/core/modules/config/tests/config_test/src/Form/ConfigTestAddForm.php
index a26814b..edda18f 100644
--- a/core/modules/config/tests/config_test/src/Form/ConfigTestAddForm.php
+++ b/core/modules/config/tests/config_test/src/Form/ConfigTestAddForm.php
@@ -18,7 +18,7 @@ class ConfigTestAddForm extends ConfigTestFormBase {
   /**
    * {@inheritdoc}
    */
-  public function save(array $form, FormStateInterface &$form_state) {
+  public function save(array $form, FormStateInterface $form_state) {
     parent::save($form, $form_state);
 
     drupal_set_message(String::format('%label configuration has been created.', array('%label' => $this->entity->label())));
diff --git a/core/modules/config/tests/config_test/src/Form/ConfigTestEditForm.php b/core/modules/config/tests/config_test/src/Form/ConfigTestEditForm.php
index ae833e1..003f224 100644
--- a/core/modules/config/tests/config_test/src/Form/ConfigTestEditForm.php
+++ b/core/modules/config/tests/config_test/src/Form/ConfigTestEditForm.php
@@ -18,7 +18,7 @@ class ConfigTestEditForm extends ConfigTestFormBase {
   /**
    * {@inheritdoc}
    */
-  public function save(array $form, FormStateInterface &$form_state) {
+  public function save(array $form, FormStateInterface $form_state) {
     parent::save($form, $form_state);
 
     drupal_set_message(String::format('%label configuration has been updated.', array('%label' => $this->entity->label())));
diff --git a/core/modules/config/tests/config_test/src/Form/ConfigTestFormBase.php b/core/modules/config/tests/config_test/src/Form/ConfigTestFormBase.php
index a8a857e..192020b 100644
--- a/core/modules/config/tests/config_test/src/Form/ConfigTestFormBase.php
+++ b/core/modules/config/tests/config_test/src/Form/ConfigTestFormBase.php
@@ -70,7 +70,7 @@ public function form(array $form, FormStateInterface $form_state) {
   /**
    * {@inheritdoc}
    */
-  public function save(array $form, FormStateInterface &$form_state) {
+  public function save(array $form, FormStateInterface $form_state) {
     parent::save($form, $form_state);
 
     $form_state->setRedirect('config_test.list_page');
diff --git a/core/modules/contact/src/Form/CategoryAddForm.php b/core/modules/contact/src/Form/CategoryAddForm.php
index 23ec3fc..2c295e1 100644
--- a/core/modules/contact/src/Form/CategoryAddForm.php
+++ b/core/modules/contact/src/Form/CategoryAddForm.php
@@ -18,7 +18,7 @@ class CategoryAddForm extends CategoryFormBase {
   /**
    * {@inheritdoc}
    */
-  public function save(array $form, FormStateInterface &$form_state) {
+  public function save(array $form, FormStateInterface $form_state) {
     parent::save($form, $form_state);
 
     $category = $this->entity;
diff --git a/core/modules/contact/src/Form/CategoryEditForm.php b/core/modules/contact/src/Form/CategoryEditForm.php
index ceedc0f..82656c9 100644
--- a/core/modules/contact/src/Form/CategoryEditForm.php
+++ b/core/modules/contact/src/Form/CategoryEditForm.php
@@ -18,7 +18,7 @@ class CategoryEditForm extends CategoryFormBase {
   /**
    * {@inheritdoc}
    */
-  public function save(array $form, FormStateInterface &$form_state) {
+  public function save(array $form, FormStateInterface $form_state) {
     parent::save($form, $form_state);
 
     $block_type = $this->entity;
diff --git a/core/modules/menu_ui/src/Form/MenuAddForm.php b/core/modules/menu_ui/src/Form/MenuAddForm.php
index 60794af..8269db6 100644
--- a/core/modules/menu_ui/src/Form/MenuAddForm.php
+++ b/core/modules/menu_ui/src/Form/MenuAddForm.php
@@ -17,7 +17,7 @@ class MenuAddForm extends MenuFormBase {
   /**
    * {@inheritdoc}
    */
-  public function save(array $form, FormStateInterface &$form_state) {
+  public function save(array $form, FormStateInterface $form_state) {
     parent::save($form, $form_state);
 
     $menu = $this->entity;
diff --git a/core/modules/menu_ui/src/Form/MenuEditForm.php b/core/modules/menu_ui/src/Form/MenuEditForm.php
index f53360f..2845fb6 100644
--- a/core/modules/menu_ui/src/Form/MenuEditForm.php
+++ b/core/modules/menu_ui/src/Form/MenuEditForm.php
@@ -17,7 +17,7 @@ class MenuEditForm extends MenuFormBase {
   /**
    * {@inheritdoc}
    */
-  public function save(array $form, FormStateInterface &$form_state) {
+  public function save(array $form, FormStateInterface $form_state) {
     parent::save($form, $form_state);
 
     $menu = $this->entity;
diff --git a/core/modules/node/src/Form/NodeAddForm.php b/core/modules/node/src/Form/NodeAddForm.php
index 21f4a0f..9eb4734 100644
--- a/core/modules/node/src/Form/NodeAddForm.php
+++ b/core/modules/node/src/Form/NodeAddForm.php
@@ -17,7 +17,7 @@ class NodeAddForm extends NodeFormBase {
   /**
    * {@inheritdoc}
    */
-  public function save(array $form, FormStateInterface &$form_state) {
+  public function save(array $form, FormStateInterface $form_state) {
     parent::save($form, $form_state);
 
     /** @var \Drupal\node\NodeInterface $node */
diff --git a/core/modules/node/src/Form/NodeEditForm.php b/core/modules/node/src/Form/NodeEditForm.php
index 93dd5fc..87f1956 100644
--- a/core/modules/node/src/Form/NodeEditForm.php
+++ b/core/modules/node/src/Form/NodeEditForm.php
@@ -17,7 +17,7 @@ class NodeEditForm extends NodeFormBase {
   /**
    * {@inheritdoc}
    */
-  public function save(array $form, FormStateInterface &$form_state) {
+  public function save(array $form, FormStateInterface $form_state) {
     parent::save($form, $form_state);
 
     /** @var \Drupal\node\NodeInterface $node */
diff --git a/core/modules/node/src/Form/NodeTypeAddForm.php b/core/modules/node/src/Form/NodeTypeAddForm.php
index 6639d67..f09d2ee 100644
--- a/core/modules/node/src/Form/NodeTypeAddForm.php
+++ b/core/modules/node/src/Form/NodeTypeAddForm.php
@@ -17,7 +17,7 @@ class NodeTypeAddForm extends NodeTypeFormBase {
   /**
    * {@inheritdoc}
    */
-  public function save(array $form, FormStateInterface &$form_state) {
+  public function save(array $form, FormStateInterface $form_state) {
     parent::save($form, $form_state);
 
     $type = $this->entity;
diff --git a/core/modules/node/src/Form/NodeTypeEditForm.php b/core/modules/node/src/Form/NodeTypeEditForm.php
index b80e72a..d9c7774 100644
--- a/core/modules/node/src/Form/NodeTypeEditForm.php
+++ b/core/modules/node/src/Form/NodeTypeEditForm.php
@@ -17,7 +17,7 @@ class NodeTypeEditForm extends NodeTypeFormBase {
   /**
    * {@inheritdoc}
    */
-  public function save(array $form, FormStateInterface &$form_state) {
+  public function save(array $form, FormStateInterface $form_state) {
     parent::save($form, $form_state);
 
     $type = $this->entity;
diff --git a/core/modules/system/tests/modules/entity_test/src/Form/EntityTestAddForm.php b/core/modules/system/tests/modules/entity_test/src/Form/EntityTestAddForm.php
index 2c75426..27ccfc9 100644
--- a/core/modules/system/tests/modules/entity_test/src/Form/EntityTestAddForm.php
+++ b/core/modules/system/tests/modules/entity_test/src/Form/EntityTestAddForm.php
@@ -17,7 +17,7 @@ class EntityTestAddForm extends EntityTestFormBase {
   /**
    * {@inheritdoc}
    */
-  public function save(array $form, FormStateInterface &$form_state) {
+  public function save(array $form, FormStateInterface $form_state) {
     parent::save($form, $form_state);
 
     $entity = $this->entity;
diff --git a/core/modules/system/tests/modules/entity_test/src/Form/EntityTestEditForm.php b/core/modules/system/tests/modules/entity_test/src/Form/EntityTestEditForm.php
index 730429e..add4317 100644
--- a/core/modules/system/tests/modules/entity_test/src/Form/EntityTestEditForm.php
+++ b/core/modules/system/tests/modules/entity_test/src/Form/EntityTestEditForm.php
@@ -17,7 +17,7 @@ class EntityTestEditForm extends EntityTestFormBase {
   /**
    * {@inheritdoc}
    */
-  public function save(array $form, FormStateInterface &$form_state) {
+  public function save(array $form, FormStateInterface $form_state) {
     parent::save($form, $form_state);
 
     $entity = $this->entity;
diff --git a/core/modules/system/tests/modules/entity_test/src/Form/EntityTestFormBase.php b/core/modules/system/tests/modules/entity_test/src/Form/EntityTestFormBase.php
index ab29d0f..5b10da4 100644
--- a/core/modules/system/tests/modules/entity_test/src/Form/EntityTestFormBase.php
+++ b/core/modules/system/tests/modules/entity_test/src/Form/EntityTestFormBase.php
@@ -79,7 +79,7 @@ public function submit(array $form, FormStateInterface $form_state) {
   /**
    * {@inheritdoc}
    */
-  public function save(array $form, FormStateInterface &$form_state) {
+  public function save(array $form, FormStateInterface $form_state) {
     parent::save($form, $form_state);
 
     $entity = $this->entity;
diff --git a/core/modules/taxonomy/src/Form/TermDeleteForm.php b/core/modules/taxonomy/src/Form/TermDeleteForm.php
index 2175dfe..c50a68a 100644
--- a/core/modules/taxonomy/src/Form/TermDeleteForm.php
+++ b/core/modules/taxonomy/src/Form/TermDeleteForm.php
@@ -56,7 +56,7 @@ public function getConfirmText() {
   /**
    * {@inheritdoc}
    */
-  public function save(array $form, FormStateInterface &$form_state) {
+  public function save(array $form, FormStateInterface $form_state) {
     parent::save($form, $form_state);
 
     $storage = $this->entityManager->getStorage('taxonomy_vocabulary');
diff --git a/core/modules/taxonomy/src/Form/VocabularyAddForm.php b/core/modules/taxonomy/src/Form/VocabularyAddForm.php
index 9bfd978..cfaad2c 100644
--- a/core/modules/taxonomy/src/Form/VocabularyAddForm.php
+++ b/core/modules/taxonomy/src/Form/VocabularyAddForm.php
@@ -17,7 +17,7 @@ class VocabularyAddForm extends VocabularyFormBase {
   /**
    * {@inheritdoc}
    */
-  public function save(array $form, FormStateInterface &$form_state) {
+  public function save(array $form, FormStateInterface $form_state) {
     parent::save($form, $form_state);
 
     $vocabulary = $this->entity;
diff --git a/core/modules/taxonomy/src/Form/VocabularyEditForm.php b/core/modules/taxonomy/src/Form/VocabularyEditForm.php
index 4f85359..a55741a 100644
--- a/core/modules/taxonomy/src/Form/VocabularyEditForm.php
+++ b/core/modules/taxonomy/src/Form/VocabularyEditForm.php
@@ -17,7 +17,7 @@ class VocabularyEditForm extends VocabularyFormBase {
   /**
    * {@inheritdoc}
    */
-  public function save(array $form, FormStateInterface &$form_state) {
+  public function save(array $form, FormStateInterface $form_state) {
     parent::save($form, $form_state);
 
     $vocabulary = $this->entity;
diff --git a/core/modules/user/src/Form/RoleAddForm.php b/core/modules/user/src/Form/RoleAddForm.php
index 1b01ee1..fa06c88 100644
--- a/core/modules/user/src/Form/RoleAddForm.php
+++ b/core/modules/user/src/Form/RoleAddForm.php
@@ -17,7 +17,7 @@ class RoleAddForm extends RoleFormBase {
   /**
    * {@inheritdoc}
    */
-  public function save(array $form, FormStateInterface &$form_state) {
+  public function save(array $form, FormStateInterface $form_state) {
     parent::save($form, $form_state);
 
     $entity = $this->entity;
diff --git a/core/modules/user/src/Form/RoleEditForm.php b/core/modules/user/src/Form/RoleEditForm.php
index 40984c6..d724efe 100644
--- a/core/modules/user/src/Form/RoleEditForm.php
+++ b/core/modules/user/src/Form/RoleEditForm.php
@@ -17,7 +17,7 @@ class RoleEditForm extends RoleFormBase {
   /**
    * {@inheritdoc}
    */
-  public function save(array $form, FormStateInterface &$form_state) {
+  public function save(array $form, FormStateInterface $form_state) {
     parent::save($form, $form_state);
 
     $entity = $this->entity;
diff --git a/core/modules/user/src/ProfileForm.php b/core/modules/user/src/ProfileForm.php
index bdb2d37..3f97e8f 100644
--- a/core/modules/user/src/ProfileForm.php
+++ b/core/modules/user/src/ProfileForm.php
@@ -46,7 +46,7 @@ protected function actions(array $form, FormStateInterface $form_state) {
   /**
    * {@inheritdoc}
    */
-  public function save(array $form, FormStateInterface &$form_state) {
+  public function save(array $form, FormStateInterface $form_state) {
     parent::save($form, $form_state);
 
     $account = $this->entity;
diff --git a/core/modules/user/src/RegisterForm.php b/core/modules/user/src/RegisterForm.php
index 44b31f9..a4d00ea 100644
--- a/core/modules/user/src/RegisterForm.php
+++ b/core/modules/user/src/RegisterForm.php
@@ -97,7 +97,7 @@ public function submit(array $form, FormStateInterface $form_state) {
   /**
    * Overrides Drupal\Core\Entity\EntityForm::submit().
    */
-  public function save(array $form, FormStateInterface &$form_state) {
+  public function save(array $form, FormStateInterface $form_state) {
     parent::save($form, $form_state);
 
     $account = $this->entity;