diff --git a/core/lib/Drupal/Component/Utility/Html.php b/core/lib/Drupal/Component/Utility/Html.php
index a775cdb..a88555d 100644
--- a/core/lib/Drupal/Component/Utility/Html.php
+++ b/core/lib/Drupal/Component/Utility/Html.php
@@ -54,10 +54,10 @@ class Html {
    *   The cleaned class name.
    */
   public static function getClass($class) {
-    if (!isset(static::$classes[$class])) {
-      static::$classes[$class] = static::cleanCssIdentifier(Unicode::strtolower($class));
+    if (!isset(static::$classes[(string) $class])) {
+      static::$classes[(string) $class] = static::cleanCssIdentifier(Unicode::strtolower($class));
     }
-    return static::$classes[$class];
+    return static::$classes[(string) $class];
   }
 
   /**
diff --git a/core/lib/Drupal/Core/Entity/EntityManager.php b/core/lib/Drupal/Core/Entity/EntityManager.php
index 351361f..80f6fd3 100644
--- a/core/lib/Drupal/Core/Entity/EntityManager.php
+++ b/core/lib/Drupal/Core/Entity/EntityManager.php
@@ -945,7 +945,7 @@ public function getEntityTypeLabels($group = FALSE) {
 
     foreach ($definitions as $entity_type_id => $definition) {
       if ($group) {
-        $options[$definition->getGroupLabel()][$entity_type_id] = $definition->getLabel();
+        $options[(string) $definition->getGroupLabel()][$entity_type_id] = $definition->getLabel();
       }
       else {
         $options[$entity_type_id] = $definition->getLabel();
@@ -959,7 +959,7 @@ public function getEntityTypeLabels($group = FALSE) {
       }
 
       // Make sure that the 'Content' group is situated at the top.
-      $content = $this->t('Content', array(), array('context' => 'Entity type group'));
+      $content = (string) $this->t('Content', array(), array('context' => 'Entity type group'));
       $options = array($content => $options[$content]) + $options;
     }
 
diff --git a/core/modules/ckeditor/ckeditor.admin.inc b/core/modules/ckeditor/ckeditor.admin.inc
index 21be21d..6c42d72 100644
--- a/core/modules/ckeditor/ckeditor.admin.inc
+++ b/core/modules/ckeditor/ckeditor.admin.inc
@@ -113,6 +113,8 @@ function template_preprocess_ckeditor_settings_toolbar(&$variables) {
   $variables['active_buttons'] = array();
   foreach ($active_buttons as $row_number => $button_row) {
     foreach ($button_groups[$row_number] as $group_name) {
+      // @todo fix this
+      $group_name = (string) $group_name;
       $variables['active_buttons'][$row_number][$group_name] = array(
         'group_name_class' => Html::getClass($group_name),
         'buttons' => array(),
diff --git a/core/modules/comment/comment.module b/core/modules/comment/comment.module
index 20ba4a3..afb7c7d 100644
--- a/core/modules/comment/comment.module
+++ b/core/modules/comment/comment.module
@@ -299,7 +299,7 @@ function comment_form_field_ui_field_storage_add_form_alter(&$form, FormStateInt
   }
   if (!_comment_entity_uses_integer_id($form_state->get('entity_type_id'))) {
     // You cannot use comment fields on entity types with non-integer IDs.
-    unset($form['add']['new_storage_type']['#options'][t('General')]['comment']);
+    unset($form['add']['new_storage_type']['#options']['general']['comment']);
   }
 }
 
diff --git a/core/modules/entity_reference/entity_reference.module b/core/modules/entity_reference/entity_reference.module
index e206dee..fbd9081 100644
--- a/core/modules/entity_reference/entity_reference.module
+++ b/core/modules/entity_reference/entity_reference.module
@@ -128,8 +128,8 @@ function entity_reference_field_config_presave(FieldConfigInterface $field) {
 function entity_reference_form_field_ui_field_storage_add_form_alter(array &$form) {
   // Move the "Entity reference" option to the end of the list and rename it to
   // "Other".
-  unset($form['add']['new_storage_type']['#options'][t('Reference')]['entity_reference']);
-  $form['add']['new_storage_type']['#options'][t('Reference')]['entity_reference'] = t('Other…');
+  unset($form['add']['new_storage_type']['#options']['reference']['entity_reference']);
+  $form['add']['new_storage_type']['#options']['reference']['entity_reference'] = t('Other…');
 }
 
 /**
diff --git a/core/modules/language/src/Form/NegotiationBrowserForm.php b/core/modules/language/src/Form/NegotiationBrowserForm.php
index bf0ce4e..5fa186a 100644
--- a/core/modules/language/src/Form/NegotiationBrowserForm.php
+++ b/core/modules/language/src/Form/NegotiationBrowserForm.php
@@ -82,8 +82,8 @@ public function buildForm(array $form, FormStateInterface $form_state) {
     }
     else {
       $language_options = array(
-        $this->t('Existing languages') => $existing_languages,
-        $this->t('Languages not yet added') => $this->languageManager->getStandardLanguageListWithoutConfigured(),
+        (string) $this->t('Existing languages') => $existing_languages,
+        (string) $this->t('Languages not yet added') => $this->languageManager->getStandardLanguageListWithoutConfigured(),
       );
     }
 
diff --git a/core/modules/locale/src/Form/ImportForm.php b/core/modules/locale/src/Form/ImportForm.php
index 1728879..f3007f6 100644
--- a/core/modules/locale/src/Form/ImportForm.php
+++ b/core/modules/locale/src/Form/ImportForm.php
@@ -94,8 +94,8 @@ public function buildForm(array $form, FormStateInterface $form_state) {
     else {
       $default = key($existing_languages);
       $language_options = array(
-        $this->t('Existing languages') => $existing_languages,
-        $this->t('Languages not yet added') => $this->languageManager->getStandardLanguageListWithoutConfigured(),
+        (string) $this->t('Existing languages') => $existing_languages,
+        (string) $this->t('Languages not yet added') => $this->languageManager->getStandardLanguageListWithoutConfigured(),
       );
     }
 
diff --git a/core/modules/views/src/Plugin/views/area/TokenizeAreaPluginBase.php b/core/modules/views/src/Plugin/views/area/TokenizeAreaPluginBase.php
index 82bb51d..8e8c719 100644
--- a/core/modules/views/src/Plugin/views/area/TokenizeAreaPluginBase.php
+++ b/core/modules/views/src/Plugin/views/area/TokenizeAreaPluginBase.php
@@ -53,13 +53,13 @@ public function tokenForm(&$form, FormStateInterface $form_state) {
     // Get a list of the available fields and arguments for token replacement.
     $options = array();
     foreach ($this->view->display_handler->getHandlers('field') as $field => $handler) {
-      $options[t('Fields')]["[$field]"] = $handler->adminLabel();
+      $options['fields']["[$field]"] = $handler->adminLabel();
     }
 
     $count = 0; // This lets us prepare the key as we want it printed.
     foreach ($this->view->display_handler->getHandlers('argument') as $handler) {
-      $options[t('Arguments')]['%' . ++$count] = $this->t('@argument title', array('@argument' => $handler->adminLabel()));
-      $options[t('Arguments')]['!' . $count] = $this->t('@argument input', array('@argument' => $handler->adminLabel()));
+      $options['arguments']['%' . ++$count] = $this->t('@argument title', array('@argument' => $handler->adminLabel()));
+      $options['arguments']['!' . $count] = $this->t('@argument input', array('@argument' => $handler->adminLabel()));
     }
 
     if (!empty($options)) {
diff --git a/core/modules/views/src/Plugin/views/display/DisplayPluginBase.php b/core/modules/views/src/Plugin/views/display/DisplayPluginBase.php
index f9ae57a..0624fc5 100644
--- a/core/modules/views/src/Plugin/views/display/DisplayPluginBase.php
+++ b/core/modules/views/src/Plugin/views/display/DisplayPluginBase.php
@@ -1728,8 +1728,8 @@ public function buildOptionsForm(&$form, FormStateInterface $form_state) {
         $options = array();
         $count = 0; // This lets us prepare the key as we want it printed.
         foreach ($this->view->display_handler->getHandlers('argument') as $handler) {
-          $options[t('Arguments')]['%' . ++$count] = $this->t('@argument title', array('@argument' => $handler->adminLabel()));
-          $options[t('Arguments')]['!' . $count] = $this->t('@argument input', array('@argument' => $handler->adminLabel()));
+          $options[(string) t('Arguments')]['%' . ++$count] = $this->t('@argument title', array('@argument' => $handler->adminLabel()));
+          $options[(string) t('Arguments')]['!' . $count] = $this->t('@argument input', array('@argument' => $handler->adminLabel()));
         }
 
         // Default text.
diff --git a/core/modules/views/src/Plugin/views/field/FieldPluginBase.php b/core/modules/views/src/Plugin/views/field/FieldPluginBase.php
index 152d4e9..455c95f 100644
--- a/core/modules/views/src/Plugin/views/field/FieldPluginBase.php
+++ b/core/modules/views/src/Plugin/views/field/FieldPluginBase.php
@@ -863,18 +863,18 @@ public function buildOptionsForm(&$form, FormStateInterface $form_state) {
       // Setup the tokens for fields.
       $previous = $this->getPreviousFieldLabels();
       foreach ($previous as $id => $label) {
-        $options[t('Fields')]["{{ $id }}"] = substr(strrchr($label, ":"), 2 );
+        $options['fields']["{{ $id }}"] = substr(strrchr($label, ":"), 2 );
       }
       // Add the field to the list of options.
-      $options[t('Fields')]["{{ {$this->options['id']} }}"] = substr(strrchr($this->adminLabel(), ":"), 2 );
+      $options['fields']["{{ {$this->options['id']} }}"] = substr(strrchr($this->adminLabel(), ":"), 2 );
 
       $count = 0; // This lets us prepare the key as we want it printed.
       foreach ($this->view->display_handler->getHandlers('argument') as $arg => $handler) {
-        $options[t('Arguments')]['%' . ++$count] = $this->t('@argument title', array('@argument' => $handler->adminLabel()));
-        $options[t('Arguments')]['!' . $count] = $this->t('@argument input', array('@argument' => $handler->adminLabel()));
+        $options['arguments']['%' . ++$count] = $this->t('@argument title', array('@argument' => $handler->adminLabel()));
+        $options['arguments']['!' . $count] = $this->t('@argument input', array('@argument' => $handler->adminLabel()));
       }
 
-      $this->documentSelfTokens($options[t('Fields')]);
+      $this->documentSelfTokens($options[$fields]);
 
       // Default text.
 
diff --git a/core/modules/views_ui/admin.inc b/core/modules/views_ui/admin.inc
index 78be0fc..b6462ea 100644
--- a/core/modules/views_ui/admin.inc
+++ b/core/modules/views_ui/admin.inc
@@ -94,16 +94,18 @@ function views_ui_add_ajax_trigger(&$wrapping_element, $trigger_key, $refresh_pa
   // always give the button a unique #value, rather than playing around with
   // #name.
   $button_title = !empty($triggering_element['#title']) ? $triggering_element['#title'] : $trigger_key;
-  if (empty($seen_buttons[$button_title])) {
+  $button_title_string = (string) $button_title;
+  if (empty($seen_buttons[$button_title_string])) {
+    // This code relies on check_plain()'ing the string because of the quotes.
     $wrapping_element[$button_key]['#value'] = t('Update "@title" choice', array(
       '@title' => $button_title,
     ));
-    $seen_buttons[$button_title] = 1;
+    $seen_buttons[$button_title_string] = 1;
   }
   else {
     $wrapping_element[$button_key]['#value'] = t('Update "@title" choice (@number)', array(
       '@title' => $button_title,
-      '@number' => ++$seen_buttons[$button_title],
+      '@number' => ++$seen_buttons[$button_title_string],
     ));
   }