diff --git a/core/includes/form.inc b/core/includes/form.inc
index 42206a4..b4c43f9 100644
--- a/core/includes/form.inc
+++ b/core/includes/form.inc
@@ -983,7 +983,7 @@ function form_select_options($element, $choices = NULL) {
       $options .= form_select_options($element, $choice);
       $options .= '</optgroup>';
     }
-    elseif (is_object($choice)) {
+    elseif (is_object($choice) && property_exists($choice, 'option')) {
       $options .= form_select_options($element, $choice->option);
     }
     else {
diff --git a/core/lib/Drupal/Core/Annotation/Translation.php b/core/lib/Drupal/Core/Annotation/Translation.php
index ad32b5e..b33beee 100644
--- a/core/lib/Drupal/Core/Annotation/Translation.php
+++ b/core/lib/Drupal/Core/Annotation/Translation.php
@@ -55,11 +55,25 @@ class Translation extends AnnotationBase {
   use StringTranslationTrait;
 
   /**
-   * The translation of the value passed to the constructor of the class.
+   * The string to be translated.
    *
    * @var string
    */
-  protected $translation;
+  protected $string;
+
+  /**
+   * The translation arguments.
+   *
+   * @var array
+   */
+  protected $arguments;
+
+  /**
+   * The translation options.
+   *
+   * @var array
+   */
+  protected $options;
 
   /**
    * Constructs a new class instance.
@@ -75,22 +89,45 @@ class Translation extends AnnotationBase {
    *   - context (optional): a string that describes the context of "value";
    */
   public function __construct(array $values) {
-    $string = $values['value'];
-    $arguments = isset($values['arguments']) ? $values['arguments'] : array();
-    $options = array();
+    $this->string = $values['value'];
+    $this->arguments = isset($values['arguments']) ? $values['arguments'] : array();
+    $this->options = array();
     if (!empty($values['context'])) {
-      $options = array(
+      $this->options = array(
         'context' => $values['context'],
       );
     }
-    $this->translation = $this->t($string, $arguments, $options);
   }
 
   /**
-   * Implements Drupal\Core\Annotation\AnnotationInterface::get().
+   * {@inheritdoc}
    */
   public function get() {
-    return $this->translation;
+    return $this;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function __toString() {
+    return $this->render();
+  }
+
+  /**
+   * Renders the object as a string.
+   *
+   * @return string
+   *   The translated string.
+   */
+  public function render() {
+    return $this->t($this->string, $this->arguments, $this->options);
+  }
+
+  /**
+   * Magic __sleep() method to avoid serializing the string translator.
+   */
+  function __sleep() {
+    return array('string', 'arguments', 'options');
   }
 
 }
diff --git a/core/lib/Drupal/Core/Config/StorableConfigBase.php b/core/lib/Drupal/Core/Config/StorableConfigBase.php
index 4a5fd1d..581ff31 100644
--- a/core/lib/Drupal/Core/Config/StorableConfigBase.php
+++ b/core/lib/Drupal/Core/Config/StorableConfigBase.php
@@ -183,6 +183,9 @@ protected function castValue($key, $value) {
     if ($element && ($element instanceof Undefined || $element instanceof Ignore)) {
       return $value;
     }
+    if (is_object($value) && method_exists($value, '__toString')) {
+      $value = (string) $value;
+    }
     if ((is_scalar($value) || $value === NULL)) {
       if ($element && $element instanceof PrimitiveInterface) {
         // Special handling for integers and floats since the configuration
diff --git a/core/lib/Drupal/Core/Form/OptGroup.php b/core/lib/Drupal/Core/Form/OptGroup.php
index f94d62d..745ef13 100644
--- a/core/lib/Drupal/Core/Form/OptGroup.php
+++ b/core/lib/Drupal/Core/Form/OptGroup.php
@@ -43,7 +43,7 @@ public static function flattenOptions(array $array) {
    */
   protected static function doFlattenOptions(array $array, array &$options) {
     foreach ($array as $key => $value) {
-      if (is_object($value)) {
+      if (is_object($value) && property_exists($value, 'option')) {
         static::doFlattenOptions($value->option, $options);
       }
       elseif (is_array($value)) {
diff --git a/core/modules/block/src/BlockBase.php b/core/modules/block/src/BlockBase.php
index 68f5f36..958da0b 100644
--- a/core/modules/block/src/BlockBase.php
+++ b/core/modules/block/src/BlockBase.php
@@ -36,7 +36,7 @@ public function label() {
     }
 
     $definition = $this->getPluginDefinition();
-    return $definition['admin_label'];
+    return (string) $definition['admin_label'];
   }
 
   /**
diff --git a/core/modules/editor/src/Tests/EditorManagerTest.php b/core/modules/editor/src/Tests/EditorManagerTest.php
index 997d861..51cd285 100644
--- a/core/modules/editor/src/Tests/EditorManagerTest.php
+++ b/core/modules/editor/src/Tests/EditorManagerTest.php
@@ -82,7 +82,7 @@ public function testManager() {
     $this->editorManager->clearCachedDefinitions();
 
     // Case 2: a text editor available.
-    $this->assertIdentical(array('unicorn' => 'Unicorn Editor'), $this->editorManager->listOptions(), 'When some text editor is enabled, the manager works correctly.');
+    $this->assertIdentical('Unicorn Editor', (string) $this->editorManager->listOptions()['unicorn'], 'When some text editor is enabled, the manager works correctly.');
 
     // Case 3: a text editor available & associated (but associated only with
     // the 'Full HTML' text format).
diff --git a/core/modules/system/src/Tests/Plugin/Discovery/DiscoveryTestBase.php b/core/modules/system/src/Tests/Plugin/Discovery/DiscoveryTestBase.php
index 9d0be54..d93bfcb 100644
--- a/core/modules/system/src/Tests/Plugin/Discovery/DiscoveryTestBase.php
+++ b/core/modules/system/src/Tests/Plugin/Discovery/DiscoveryTestBase.php
@@ -7,6 +7,7 @@
 
 namespace Drupal\system\Tests\Plugin\Discovery;
 
+use Drupal\Core\Annotation\Translation;
 use Drupal\simpletest\UnitTestBase;
 
 /**
@@ -49,7 +50,7 @@ function testDiscoveryInterface() {
 
     // Ensure that getDefinition() returns the expected definition.
     foreach ($this->expectedDefinitions as $id => $definition) {
-      $this->assertIdentical($this->discovery->getDefinition($id), $definition);
+      $this->assertDefinitionIdentical($this->discovery->getDefinition($id), $definition);
     }
 
     // Ensure that an empty array is returned if no plugin definitions are found.
@@ -58,5 +59,30 @@ function testDiscoveryInterface() {
     // Ensure that NULL is returned as the definition of a non-existing plugin.
     $this->assertIdentical($this->emptyDiscovery->getDefinition('non_existing', FALSE), NULL, 'NULL returned as the definition of a non-existing plugin.');
   }
+
+  /**
+   * Asserts a definition against an expected definition.
+   *
+   * Converts any instances of \Drupal\Core\Annotation\Translation to a string.
+   *
+   * @param array $definition
+   *   The definition to test.
+   * @param array $expected_definition
+   *   The expected definition to test against.
+   *
+   * @return
+   *   TRUE if the assertion succeeded, FALSE otherwise.
+   */
+  protected function assertDefinitionIdentical(array $definition, array $expected_definition) {
+    $func = function (&$item, $key){
+      if ($item instanceof Translation) {
+        $item = (string) $item;
+      }
+    };
+    array_walk_recursive($definition, $func);
+    array_walk_recursive($expected_definition, $func);
+    return $this->assertIdentical($definition, $expected_definition);
+  }
+
 }
 
diff --git a/core/modules/views/src/Plugin/views/filter/FilterPluginBase.php b/core/modules/views/src/Plugin/views/filter/FilterPluginBase.php
index 902b543..8bf44c1 100644
--- a/core/modules/views/src/Plugin/views/filter/FilterPluginBase.php
+++ b/core/modules/views/src/Plugin/views/filter/FilterPluginBase.php
@@ -1160,11 +1160,11 @@ protected function prepareFilterSelectOptions(&$options) {
       }
       // FAPI has some special value to allow hierarchy.
       // @see _form_options_flatten
-      elseif (is_object($label)) {
+      elseif (is_object($label) && property_exists($label, 'option')) {
         $this->prepareFilterSelectOptions($options[$value]->option);
       }
       else {
-        $options[$value] = strip_tags(decode_entities($label));
+        $options[$value] = strip_tags(decode_entities((string) $label));
       }
     }
   }
diff --git a/core/modules/views_ui/src/ViewListBuilder.php b/core/modules/views_ui/src/ViewListBuilder.php
index 68ad5b0..1e9d496 100644
--- a/core/modules/views_ui/src/ViewListBuilder.php
+++ b/core/modules/views_ui/src/ViewListBuilder.php
@@ -229,8 +229,8 @@ protected function getDisplaysList(EntityInterface $view) {
     $displays = array();
     foreach ($view->get('display') as $display) {
       $definition = $this->displayManager->getDefinition($display['display_plugin']);
-      if (!empty($definition['admin'])) {
-        $displays[$definition['admin']] = TRUE;
+      if (isset($definition['admin']) && $display_admin = (string) $definition['admin']) {
+        $displays[$display_admin] = TRUE;
       }
     }
 
diff --git a/core/tests/Drupal/Tests/Core/Annotation/TranslationTest.php b/core/tests/Drupal/Tests/Core/Annotation/TranslationTest.php
index 071df3e..bcfe00d 100644
--- a/core/tests/Drupal/Tests/Core/Annotation/TranslationTest.php
+++ b/core/tests/Drupal/Tests/Core/Annotation/TranslationTest.php
@@ -62,7 +62,7 @@ public function testGet(array $values, $expected) {
 
     $annotation = new Translation($values);
 
-    $this->assertSame($expected, $annotation->get());
+    $this->assertSame($expected, (string) $annotation->get());
   }
 
   /**
diff --git a/core/tests/Drupal/Tests/Core/Form/OptGroupTest.php b/core/tests/Drupal/Tests/Core/Form/OptGroupTest.php
index 0807448..febc6c6 100644
--- a/core/tests/Drupal/Tests/Core/Form/OptGroupTest.php
+++ b/core/tests/Drupal/Tests/Core/Form/OptGroupTest.php
@@ -50,11 +50,15 @@ public function providerTestFlattenOptions() {
     $object1->option = array('foo' => 'foo');
     $object2 = new \stdClass();
     $object2->option = array(array('foo' => 'foo'), array('foo' => 'foo'));
+    $object3 = new \stdClass();
     return array(
       array(array('foo' => 'foo')),
       array(array(array('foo' => 'foo'))),
       array(array($object1)),
       array(array($object2)),
+      array(array($object1, $object2)),
+      array(array('foo' => $object3)),
+      array(array('foo' => $object3, $object1, array('foo' => 'foo'))),
     );
   }