diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldWidget/OptionsWidgetBase.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldWidget/OptionsWidgetBase.php
index ca00bcc..3bcd19d 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldWidget/OptionsWidgetBase.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldWidget/OptionsWidgetBase.php
@@ -67,7 +67,7 @@ public function formElement(FieldItemListInterface $items, $delta, array $elemen
    *   The form state.
    */
   public static function validateElement(array $element, FormStateInterface $form_state) {
-    if ($element['#required'] && $element['#value'] == '_none') {
+    if ($element['#required'] && $element['#value'] == '') {
       $form_state->setError($element, t('@name field is required.', array('@name' => $element['#title'])));
     }
 
@@ -85,7 +85,7 @@ public static function validateElement(array $element, FormStateInterface $form_
 
     // Filter out the 'none' option. Use a strict comparison, because
     // 0 == 'any string'.
-    $index = array_search('_none', $values, TRUE);
+    $index = array_search('', $values, TRUE);
     if ($index !== FALSE) {
       unset($values[$index]);
     }
@@ -117,7 +117,7 @@ protected function getOptions(FieldableEntityInterface $entity) {
 
       // Add an empty option if the widget needs one.
       if ($empty_label = $this->getEmptyLabel()) {
-        $options = ['_none' => $empty_label] + $options;
+        $options = ['' => $empty_label] + $options;
       }
 
       $module_handler = \Drupal::moduleHandler();
diff --git a/core/modules/options/options.api.php b/core/modules/options/options.api.php
index 28ac771..7c00171 100644
--- a/core/modules/options/options.api.php
+++ b/core/modules/options/options.api.php
@@ -32,7 +32,7 @@ function hook_options_list_alter(array &$options, array $context) {
   // Check if this is the field we want to change.
   if ($context['fieldDefinition']->id() == 'field_option') {
     // Change the label of the empty option.
-    $options['_none'] = t('== Empty ==');
+    $options[''] = t('== Empty ==');
   }
 }
 
diff --git a/core/modules/options/src/Tests/OptionsSelectDynamicValuesTest.php b/core/modules/options/src/Tests/OptionsSelectDynamicValuesTest.php
index df3365c..5b4c7dd 100644
--- a/core/modules/options/src/Tests/OptionsSelectDynamicValuesTest.php
+++ b/core/modules/options/src/Tests/OptionsSelectDynamicValuesTest.php
@@ -25,7 +25,7 @@ function testSelectListDynamic() {
     $this->assertEqual(count($options), count($this->test) + 1);
     foreach ($options as $option) {
       $value = (string) $option['value'];
-      if ($value != '_none') {
+      if ($value != '') {
         $this->assertTrue(array_search($value, $this->test));
       }
     }
diff --git a/core/modules/options/src/Tests/OptionsWidgetsTest.php b/core/modules/options/src/Tests/OptionsWidgetsTest.php
index 23f0f0d..e6af6c2 100644
--- a/core/modules/options/src/Tests/OptionsWidgetsTest.php
+++ b/core/modules/options/src/Tests/OptionsWidgetsTest.php
@@ -125,7 +125,7 @@ function testRadioButtons() {
     $this->assertNoFieldChecked('edit-card-1-2');
 
     // Unselect option.
-    $edit = array('card_1' => '_none');
+    $edit = array('card_1' => '');
     $this->drupalPostForm(NULL, $edit, t('Save'));
     $this->assertFieldValues($entity_init, 'card_1', array());
 
@@ -255,17 +255,17 @@ function testSelectListSingle() {
     // Display form.
     $this->drupalGet('entity_test/manage/' . $entity->id() . '/edit');
     // A required field without any value has a "none" option.
-    $this->assertTrue($this->xpath('//select[@id=:id]//option[@value="_none" and text()=:label]', array(':id' => 'edit-card-1', ':label' => t('- Select a value -'))), 'A required select list has a "Select a value" choice.');
+    $this->assertTrue($this->xpath('//select[@id=:id]//option[@value="" and text()=:label]', array(':id' => 'edit-card-1', ':label' => t('- Select a value -'))), 'A required select list has a "Select a value" choice.');
 
     // With no field data, nothing is selected.
-    $this->assertNoOptionSelected('edit-card-1', '_none');
+    $this->assertNoOptionSelected('edit-card-1', '');
     $this->assertNoOptionSelected('edit-card-1', 0);
     $this->assertNoOptionSelected('edit-card-1', 1);
     $this->assertNoOptionSelected('edit-card-1', 2);
     $this->assertRaw('Some dangerous & unescaped markup', 'Option text was properly filtered.');
 
     // Submit form: select invalid 'none' option.
-    $edit = array('card_1' => '_none');
+    $edit = array('card_1' => '');
     $this->drupalPostForm(NULL, $edit, t('Save'));
     $this->assertRaw(t('@title field is required.', array('@title' => $field->getName())), 'Cannot save a required field when selecting "none" from the select list.');
 
@@ -277,7 +277,7 @@ function testSelectListSingle() {
     // Display form: check that the right options are selected.
     $this->drupalGet('entity_test/manage/' . $entity->id() . '/edit');
     // A required field with a value has no 'none' option.
-    $this->assertFalse($this->xpath('//select[@id=:id]//option[@value="_none"]', array(':id' => 'edit-card-1')), 'A required select list with an actual value has no "none" choice.');
+    $this->assertFalse($this->xpath('//select[@id=:id]//option[@value=""]', array(':id' => 'edit-card-1')), 'A required select list with an actual value has no "none" choice.');
     $this->assertOptionSelected('edit-card-1', 0);
     $this->assertNoOptionSelected('edit-card-1', 1);
     $this->assertNoOptionSelected('edit-card-1', 2);
@@ -289,9 +289,9 @@ function testSelectListSingle() {
     // Display form.
     $this->drupalGet('entity_test/manage/' . $entity->id() . '/edit');
     // A non-required field has a 'none' option.
-    $this->assertTrue($this->xpath('//select[@id=:id]//option[@value="_none" and text()=:label]', array(':id' => 'edit-card-1', ':label' => t('- None -'))), 'A non-required select list has a "None" choice.');
+    $this->assertTrue($this->xpath('//select[@id=:id]//option[@value="" and text()=:label]', array(':id' => 'edit-card-1', ':label' => t('- None -'))), 'A non-required select list has a "None" choice.');
     // Submit form: Unselect the option.
-    $edit = array('card_1' => '_none');
+    $edit = array('card_1' => '');
     $this->drupalPostForm('entity_test/manage/' . $entity->id() . '/edit', $edit, t('Save'));
     $this->assertFieldValues($entity_init, 'card_1', array());
 
@@ -322,7 +322,7 @@ function testSelectListSingle() {
     $this->assertNoOptionSelected('edit-card-1', 2);
 
     // Submit form: Unselect the option.
-    $edit = array('card_1' => '_none');
+    $edit = array('card_1' => '');
     $this->drupalPostForm('entity_test/manage/' . $entity->id() . '/edit', $edit, t('Save'));
     $this->assertFieldValues($entity_init, 'card_1', array());
   }
@@ -353,7 +353,7 @@ function testSelectListMultiple() {
 
     // Display form: with no field data, nothing is selected.
     $this->drupalGet('entity_test/manage/' . $entity->id() . '/edit');
-    $this->assertOptionSelected("edit-card-2", '_none');
+    $this->assertOptionSelected("edit-card-2", '');
     $this->assertNoOptionSelected('edit-card-2', 0);
     $this->assertNoOptionSelected('edit-card-2', 1);
     $this->assertNoOptionSelected('edit-card-2', 2);
@@ -395,12 +395,12 @@ function testSelectListMultiple() {
 
     // Check that the 'none' option has no effect if actual options are selected
     // as well.
-    $edit = array('card_2[]' => array('_none' => '_none', 0 => 0));
+    $edit = array('card_2[]' => array('' => '', 0 => 0));
     $this->drupalPostForm('entity_test/manage/' . $entity->id() . '/edit', $edit, t('Save'));
     $this->assertFieldValues($entity_init, 'card_2', array(0));
 
     // Check that selecting the 'none' option empties the field.
-    $edit = array('card_2[]' => array('_none' => '_none'));
+    $edit = array('card_2[]' => array('' => ''));
     $this->drupalPostForm('entity_test/manage/' . $entity->id() . '/edit', $edit, t('Save'));
     $this->assertFieldValues($entity_init, 'card_2', array());
 
@@ -443,7 +443,7 @@ function testSelectListMultiple() {
     $this->assertNoOptionSelected('edit-card-2', 2);
 
     // Submit form: Unselect the option.
-    $edit = array('card_2[]' => array('_none' => '_none'));
+    $edit = array('card_2[]' => array('' => ''));
     $this->drupalPostForm('entity_test/manage/' . $entity->id() . '/edit', $edit, t('Save'));
     $this->assertFieldValues($entity_init, 'card_2', array());
   }
@@ -475,7 +475,7 @@ function testEmptyValue() {
 
     // Display form: check that _none options are present and has label.
     $this->drupalGet('entity_test/manage/' . $entity->id() . '/edit');
-    $this->assertTrue($this->xpath('//div[@id=:id]//input[@value=:value]', array(':id' => 'edit-card-1', ':value' => '_none')), 'A test radio button has a "None" choice.');
+    $this->assertTrue($this->xpath('//div[@id=:id]//input[@value=:value]', array(':id' => 'edit-card-1', ':value' => '')), 'A test radio button has a "None" choice.');
     $this->assertTrue($this->xpath('//div[@id=:id]//label[@for=:for and text()=:label]', array(':id' => 'edit-card-1', ':for' => 'edit-card-1-none', ':label' => 'N/A')), 'A test radio button has a "N/A" choice.');
 
     // Change it to the select widget.
@@ -488,7 +488,7 @@ function testEmptyValue() {
     // Display form: check that _none options are present and has label.
     $this->drupalGet('entity_test/manage/' . $entity->id() . '/edit');
     // A required field without any value has a "none" option.
-    $this->assertTrue($this->xpath('//select[@id=:id]//option[@value="_none" and text()=:label]', array(':id' => 'edit-card-1', ':label' => t('- None -'))), 'A test select has a "None" choice.');
+    $this->assertTrue($this->xpath('//select[@id=:id]//option[@value="" and text()=:label]', array(':id' => 'edit-card-1', ':label' => t('- None -'))), 'A test select has a "None" choice.');
   }
 
 }