diff --git a/core/lib/Drupal/Core/Config/ConfigInstaller.php b/core/lib/Drupal/Core/Config/ConfigInstaller.php
index 2238a31..e99397e 100644
--- a/core/lib/Drupal/Core/Config/ConfigInstaller.php
+++ b/core/lib/Drupal/Core/Config/ConfigInstaller.php
@@ -225,16 +225,12 @@ protected function createConfiguration($collection, array $config_to_install) {
         if ($this->getActiveStorage($collection)->exists($name)) {
           $id = $entity_storage->getIDFromConfigName($name, $entity_storage->getEntityType()->getConfigPrefix());
           $entity = $entity_storage->load($id);
-          foreach ($new_config->get() as $property => $value) {
-            $entity->set($property, $value);
-          }
-          $entity->save();
+          $entity = $entity_storage->updateFromStorageRecord($entity, $new_config->get());
         }
         else {
-          $entity_storage
-            ->create($new_config->get())
-            ->save();
+          $entity = $entity_storage->createFromStorageRecord($new_config->get());
         }
+        $entity->save();
       }
       else {
         $new_config->save();
diff --git a/core/lib/Drupal/Core/Config/Entity/ConfigEntityStorage.php b/core/lib/Drupal/Core/Config/Entity/ConfigEntityStorage.php
index 0e071b8..4cad074 100644
--- a/core/lib/Drupal/Core/Config/Entity/ConfigEntityStorage.php
+++ b/core/lib/Drupal/Core/Config/Entity/ConfigEntityStorage.php
@@ -347,7 +347,7 @@ public function getQueryServicename() {
    * {@inheritdoc}
    */
   public function importCreate($name, Config $new_config, Config $old_config) {
-    $entity = $this->create($new_config->get());
+    $entity = $this->createFromStorageRecord($new_config->get());
     $entity->setSyncing(TRUE);
     $entity->save();
     return TRUE;
@@ -363,16 +363,7 @@ public function importUpdate($name, Config $new_config, Config $old_config) {
       throw new ConfigImporterException(String::format('Attempt to update non-existing entity "@id".', array('@id' => $id)));
     }
     $entity->setSyncing(TRUE);
-    $entity->original = clone $entity;
-
-    foreach ($old_config->get() as $property => $value) {
-      $entity->original->set($property, $value);
-    }
-
-    foreach ($new_config->get() as $property => $value) {
-      $entity->set($property, $value);
-    }
-
+    $entity = $this->updateFromStorageRecord($entity, $new_config->get());
     $entity->save();
     return TRUE;
   }
@@ -392,15 +383,44 @@ public function importDelete($name, Config $new_config, Config $old_config) {
    * {@inheritdoc}
    */
   public function importRename($old_name, Config $new_config, Config $old_config) {
-    $id = static::getIDFromConfigName($old_name, $this->entityType->getConfigPrefix());
-    $entity = $this->load($id);
-    $entity->setSyncing(TRUE);
-    $data = $new_config->get();
-    foreach ($data as $key => $value) {
-      $entity->set($key, $value);
+    return $this->importUpdate($old_name, $new_config, $old_config);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function createFromStorageRecord(array $values) {
+    // Assign a new UUID if there is none yet.
+    if ($this->uuidKey && $this->uuidService && !isset($values[$this->uuidKey])) {
+      $values[$this->uuidKey] = $this->uuidService->generate();
     }
-    $entity->save();
-    return TRUE;
+    $data = $this->mapFromStorageRecords(array($values));
+    $entity = current($data);
+    $entity->original = clone $entity;
+    $entity->enforceIsNew();
+    $entity->postCreate($this);
+
+    // Modules might need to add or change the data initially held by the new
+    // entity object, for instance to fill-in default values.
+    $this->invokeHook('create', $entity);
+    return $entity;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function updateFromStorageRecord(ConfigEntityInterface $entity, array $values) {
+    $entity->original = clone $entity;
+
+    $data = $this->mapFromStorageRecords(array($values));
+    $updated_entity = current($data);
+
+    foreach (array_keys($values) as $property) {
+      $value = $updated_entity->get($property);
+      $entity->set($property, $value);
+    }
+
+    return $entity;
   }
 
 }
diff --git a/core/lib/Drupal/Core/Config/Entity/ConfigEntityStorageInterface.php b/core/lib/Drupal/Core/Config/Entity/ConfigEntityStorageInterface.php
index c034101..62c36f9 100644
--- a/core/lib/Drupal/Core/Config/Entity/ConfigEntityStorageInterface.php
+++ b/core/lib/Drupal/Core/Config/Entity/ConfigEntityStorageInterface.php
@@ -29,4 +29,40 @@
    */
   public static function getIDFromConfigName($config_name, $config_prefix);
 
+  /**
+   * Creates a configuration entity from storage values.
+   *
+   * Allows the configuration entity storage to massage storage values before
+   * creating an entity.
+   *
+   * @param array $values
+   *   The array of values from the configuration storage.
+   *
+   * @return ConfigEntityInterface
+   *   The configuration entity.
+   *
+   * @see \Drupal\Core\Entity\EntityStorageBase::mapFromStorageRecords()
+   * @see \Drupal\field\FieldStorageConfigStorage::mapFromStorageRecords()
+   */
+  public function createFromStorageRecord(array $values);
+
+  /**
+   * Updates a configuration entity from storage values.
+   *
+   * Allows the configuration entity storage to massage storage values before
+   * updating an entity.
+   *
+   * @param ConfigEntityInterface $entity
+   *   The configuration entity to update.
+   * @param array $values
+   *   The array of values from the configuration storage.
+   *
+   * @return ConfigEntityInterface
+   *   The configuration entity.
+   *
+   * @see \Drupal\Core\Entity\EntityStorageBase::mapFromStorageRecords()
+   * @see \Drupal\field\FieldStorageConfigStorage::mapFromStorageRecords()
+   */
+  public function updateFromStorageRecord(ConfigEntityInterface $entity, array $values);
+
 }
diff --git a/core/lib/Drupal/Core/Config/Schema/SchemaCheckTrait.php b/core/lib/Drupal/Core/Config/Schema/SchemaCheckTrait.php
index 0836eaf..4d2bd11 100644
--- a/core/lib/Drupal/Core/Config/Schema/SchemaCheckTrait.php
+++ b/core/lib/Drupal/Core/Config/Schema/SchemaCheckTrait.php
@@ -94,7 +94,8 @@ protected function checkValue($key, $value) {
       if ($element instanceof PrimitiveInterface) {
         $success =
           ($type == 'integer' && $element instanceof IntegerInterface) ||
-          ($type == 'double' && $element instanceof FloatInterface) ||
+          // Allow integer values in a float field.
+          (($type == 'double' || $type == 'integer') && $element instanceof FloatInterface) ||
           ($type == 'boolean' && $element instanceof BooleanInterface) ||
           ($type == 'string' && $element instanceof StringInterface) ||
           // Null values are allowed for all types.
diff --git a/core/modules/config/src/Form/ConfigSingleImportForm.php b/core/modules/config/src/Form/ConfigSingleImportForm.php
index 5d7a541..debd1cb 100644
--- a/core/modules/config/src/Form/ConfigSingleImportForm.php
+++ b/core/modules/config/src/Form/ConfigSingleImportForm.php
@@ -246,12 +246,16 @@ public function submitForm(array &$form, FormStateInterface $form_state) {
       $this->config($this->data['config_name'])->setData($this->data['import'])->save();
       drupal_set_message($this->t('The %name configuration was imported.', array('%name' => $this->data['config_name'])));
     }
-    // For a config entity, create a new entity and save it.
+    // For a config entity, create an entity and save it.
     else {
       try {
-        $entity = $this->entityManager
-          ->getStorage($this->data['config_type'])
-          ->create($this->data['import']);
+        $entity_storage = $this->entityManager->getStorage($this->data['config_type']);
+        if ($this->configExists) {
+          $entity = $entity_storage->updateFromStorageRecord($this->configExists, $this->data['import']);
+        }
+        else {
+          $entity = $entity_storage->createFromStorageRecord($this->data['import']);
+        }
         $entity->save();
         drupal_set_message($this->t('The @entity_type %label was imported.', array('@entity_type' => $entity->getEntityTypeId(), '%label' => $entity->label())));
       }
diff --git a/core/modules/config/src/Tests/ConfigCRUDTest.php b/core/modules/config/src/Tests/ConfigCRUDTest.php
index c38d3f6..39f790e 100644
--- a/core/modules/config/src/Tests/ConfigCRUDTest.php
+++ b/core/modules/config/src/Tests/ConfigCRUDTest.php
@@ -226,6 +226,7 @@ public function testDataTypes() {
       'boolean' => TRUE,
       'exp' => 1.2e+34,
       'float' => 3.14159,
+      'float_as_integer' => (float) 1,
       'hex' => 0xC,
       'int' => 99,
       'octal' => 0775,
diff --git a/core/modules/config/src/Tests/ConfigSingleImportExportTest.php b/core/modules/config/src/Tests/ConfigSingleImportExportTest.php
index 5609f8f..7221be4 100644
--- a/core/modules/config/src/Tests/ConfigSingleImportExportTest.php
+++ b/core/modules/config/src/Tests/ConfigSingleImportExportTest.php
@@ -98,6 +98,26 @@ public function testImport() {
     $this->assertIdentical($entity->id(), 'second');
     $this->assertFalse($entity->status());
     $this->assertIdentical($entity->uuid(), $second_uuid);
+
+    // Perform an update.
+    $import = <<<EOD
+id: second
+uuid: $second_uuid
+label: 'Second updated'
+weight: 0
+style: ''
+status: '0'
+EOD;
+    $edit = array(
+      'config_type' => 'config_test',
+      'import' => $import,
+    );
+    $this->drupalPostForm('admin/config/development/configuration/single/import', $edit, t('Import'));
+    $this->assertRaw(t('Are you sure you want to update the %name @type?', array('%name' => 'second', '@type' => 'test configuration')));
+    $this->drupalPostForm(NULL, array(), t('Confirm'));
+    $entity = $storage->load('second');
+    $this->assertRaw(t('The @entity_type %label was imported.', array('@entity_type' => 'config_test', '%label' => $entity->label())));
+    $this->assertIdentical($entity->label(), 'Second updated');
   }
 
   /**
diff --git a/core/modules/config/tests/config_test/config/install/config_test.types.yml b/core/modules/config/tests/config_test/config/install/config_test.types.yml
index 4ab2cdc..060a2b0 100644
--- a/core/modules/config/tests/config_test/config/install/config_test.types.yml
+++ b/core/modules/config/tests/config_test/config/install/config_test.types.yml
@@ -2,6 +2,7 @@ array: []
 boolean: true
 exp: 1.2e+34
 float: 3.14159
+float_as_integer: 1
 hex: 0xC
 int: 99
 octal: 0775
diff --git a/core/modules/config/tests/config_test/config/schema/config_test.schema.yml b/core/modules/config/tests/config_test/config/schema/config_test.schema.yml
index 80dc9fb..a557789 100644
--- a/core/modules/config/tests/config_test/config/schema/config_test.schema.yml
+++ b/core/modules/config/tests/config_test/config/schema/config_test.schema.yml
@@ -68,6 +68,9 @@ config_test.types:
     float:
       type: float
       label: 'Float'
+    float_as_integer:
+      type: float
+      label: 'Float'
     exp:
       type: float
       label: 'Exponential'
diff --git a/core/modules/field/src/Tests/FieldImportDeleteUninstallUiTest.php b/core/modules/field/src/Tests/FieldImportDeleteUninstallUiTest.php
index d7a7b6c..939cfc4 100644
--- a/core/modules/field/src/Tests/FieldImportDeleteUninstallUiTest.php
+++ b/core/modules/field/src/Tests/FieldImportDeleteUninstallUiTest.php
@@ -102,6 +102,16 @@ public function testImportDeleteUninstall() {
     $staging->write('core.extension', $core_extension);
     $this->drupalGet('admin/config/development/configuration');
     $this->assertText('This synchronization will delete data from the fields: entity_test.field_tel, entity_test.field_text.');
+    // Delete all the text fields in staging, entity_test_install() adds quite
+    // a few.
+    foreach (\Drupal::entityManager()->getFieldMap() as $entity_type => $fields) {
+      foreach ($fields as $field_name => $info) {
+        if ($info['type'] == 'text') {
+          $staging->delete("field.storage.$entity_type.$field_name");
+          $staging->delete("field.field.$entity_type.$entity_type.$field_name");
+        }
+      }
+    }
 
     // This will purge all the data, delete the field and uninstall the
     // Telephone and Text modules.
diff --git a/core/modules/options/src/Tests/OptionsFloatFieldImportTest.php b/core/modules/options/src/Tests/OptionsFloatFieldImportTest.php
new file mode 100644
index 0000000..0f8414f
--- /dev/null
+++ b/core/modules/options/src/Tests/OptionsFloatFieldImportTest.php
@@ -0,0 +1,77 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\options\Tests\OptionsFloatFieldImportTest.
+ */
+
+namespace Drupal\options\Tests;
+
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\field\Tests\FieldTestBase;
+
+/**
+ * Tests option fields can be updated and created through config synchronization.
+ *
+ * @group options
+ */
+class OptionsFloatFieldImportTest extends FieldTestBase {
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  public static $modules = array('node', 'options', 'field_ui', 'config', 'options_config_install_test');
+
+  protected function setUp() {
+    parent::setUp();
+
+    // Create test user.
+    $admin_user = $this->drupalCreateUser(array('synchronize configuration', 'access content', 'access administration pages', 'administer site configuration', 'administer content types', 'administer nodes', 'bypass node access', 'administer node fields', 'administer node display'));
+    $this->drupalLogin($admin_user);
+  }
+
+  /**
+   * Tests that importing list_float fields works.
+   */
+  public function testImport() {
+    $field_name = 'field_options_float';
+    $type = 'options_install_test';
+
+    // Test the results on installing options_config_install_test. All the
+    // necessary configuration for this test is created by installing that
+    // module.
+    $field_storage = FieldStorageConfig::loadByName('node', $field_name);
+    $this->assertIdentical($field_storage->getSetting('allowed_values'), $array = array('0' => 'Zero', '0.5' => 'Point five'));
+
+    $admin_path = 'admin/structure/types/manage/' . $type . '/fields/node.' . $type . '.' . $field_name . '/storage';
+
+    // Export active config to staging
+    $this->copyConfig($this->container->get('config.storage'), $this->container->get('config.storage.staging'));
+
+    // Set the active to not use dots in the allowed values key names.
+    $edit = array('field_storage[settings][allowed_values]' => "0|Zero\n1|One");
+    $this->drupalPostForm($admin_path, $edit, t('Save field settings'));
+    $field_storage = FieldStorageConfig::loadByName('node', $field_name);
+    $this->assertIdentical($field_storage->getSetting('allowed_values'), $array = array('0' => 'Zero', '1' => 'One'));
+
+    // Import configuration with dots in the allowed values key names. This
+    // tests \Drupal\Core\Config\Entity\ConfigEntityStorage::importUpdate().
+    $this->drupalGet('admin/config/development/configuration');
+    $this->drupalPostForm(NULL, array(), t('Import all'));
+    $field_storage = FieldStorageConfig::loadByName('node', $field_name);
+    $this->assertIdentical($field_storage->getSetting('allowed_values'), $array = array('0' => 'Zero', '0.5' => 'Point five'));
+
+    // Delete field to test creation. This tests
+    // \Drupal\Core\Config\Entity\ConfigEntityStorage::importCreate().
+    FieldConfig::loadByName('node', $type, $field_name)->delete();
+
+    $this->drupalGet('admin/config/development/configuration');
+    $this->drupalPostForm(NULL, array(), t('Import all'));
+    $field_storage = FieldStorageConfig::loadByName('node', $field_name);
+    $this->assertIdentical($field_storage->getSetting('allowed_values'), $array = array('0' => 'Zero', '0.5' => 'Point five'));
+  }
+
+}
diff --git a/core/modules/options/tests/options_config_install_test/config/install/core.entity_form_display.node.options_install_test.default.yml b/core/modules/options/tests/options_config_install_test/config/install/core.entity_form_display.node.options_install_test.default.yml
new file mode 100644
index 0000000..3b96a57
--- /dev/null
+++ b/core/modules/options/tests/options_config_install_test/config/install/core.entity_form_display.node.options_install_test.default.yml
@@ -0,0 +1,57 @@
+langcode: en
+status: true
+dependencies:
+  entity:
+    - field.field.node.options_install_test.body
+    - node.type.options_install_test
+  module:
+    - entity_reference
+    - text
+id: node.options_install_test.default
+targetEntityType: node
+bundle: options_install_test
+mode: default
+content:
+  title:
+    type: string_textfield
+    weight: -5
+    settings:
+      size: 60
+      placeholder: ''
+    third_party_settings: {  }
+  uid:
+    type: entity_reference_autocomplete
+    weight: 5
+    settings:
+      match_operator: CONTAINS
+      size: 60
+      autocomplete_type: tags
+      placeholder: ''
+    third_party_settings: {  }
+  created:
+    type: datetime_timestamp
+    weight: 10
+    settings: {  }
+    third_party_settings: {  }
+  promote:
+    type: boolean_checkbox
+    settings:
+      display_label: '1'
+    weight: 15
+    third_party_settings: {  }
+  sticky:
+    type: boolean_checkbox
+    settings:
+      display_label: '1'
+    weight: 16
+    third_party_settings: {  }
+  body:
+    type: text_textarea_with_summary
+    weight: 26
+    settings:
+      rows: 9
+      summary_rows: 3
+      placeholder: ''
+    third_party_settings: {  }
+hidden: {  }
+third_party_settings: {  }
diff --git a/core/modules/options/tests/options_config_install_test/config/install/core.entity_view_display.node.options_install_test.default.yml b/core/modules/options/tests/options_config_install_test/config/install/core.entity_view_display.node.options_install_test.default.yml
new file mode 100644
index 0000000..506ee9d
--- /dev/null
+++ b/core/modules/options/tests/options_config_install_test/config/install/core.entity_view_display.node.options_install_test.default.yml
@@ -0,0 +1,28 @@
+langcode: en
+status: true
+dependencies:
+  entity:
+    - field.field.node.options_install_test.body
+    - node.type.options_install_test
+  module:
+    - text
+    - user
+id: node.options_install_test.default
+label: null
+targetEntityType: node
+bundle: options_install_test
+mode: default
+content:
+  links:
+    weight: 100
+  body:
+    label: hidden
+    type: text_default
+    weight: 101
+    settings: {  }
+    third_party_settings: {  }
+hidden:
+  langcode: true
+third_party_settings:
+  entity_test:
+    foo: bar
diff --git a/core/modules/options/tests/options_config_install_test/config/install/core.entity_view_display.node.options_install_test.teaser.yml b/core/modules/options/tests/options_config_install_test/config/install/core.entity_view_display.node.options_install_test.teaser.yml
new file mode 100644
index 0000000..356a6a2
--- /dev/null
+++ b/core/modules/options/tests/options_config_install_test/config/install/core.entity_view_display.node.options_install_test.teaser.yml
@@ -0,0 +1,30 @@
+langcode: en
+status: true
+dependencies:
+  entity:
+    - core.entity_view_mode.node.teaser
+    - field.field.node.options_install_test.body
+    - node.type.options_install_test
+  module:
+    - text
+    - user
+id: node.options_install_test.teaser
+label: null
+targetEntityType: node
+bundle: options_install_test
+mode: teaser
+content:
+  links:
+    weight: 100
+  body:
+    label: hidden
+    type: text_summary_or_trimmed
+    weight: 101
+    settings:
+      trim_length: 600
+    third_party_settings: {  }
+hidden:
+  langcode: true
+third_party_settings:
+  entity_test:
+    foo: bar
diff --git a/core/modules/options/tests/options_config_install_test/config/install/field.field.node.options_install_test.body.yml b/core/modules/options/tests/options_config_install_test/config/install/field.field.node.options_install_test.body.yml
new file mode 100644
index 0000000..20fd4d3
--- /dev/null
+++ b/core/modules/options/tests/options_config_install_test/config/install/field.field.node.options_install_test.body.yml
@@ -0,0 +1,20 @@
+langcode: en
+status: true
+dependencies:
+  entity:
+    - field.storage.node.body
+    - node.type.options_install_test
+id: node.options_install_test.body
+field_name: body
+entity_type: node
+bundle: options_install_test
+label: Body
+description: ''
+required: false
+translatable: true
+default_value: {  }
+default_value_callback: ''
+settings:
+  display_summary: true
+third_party_settings: {  }
+field_type: text_with_summary
diff --git a/core/modules/options/tests/options_config_install_test/config/install/field.field.node.options_install_test.field_options_float.yml b/core/modules/options/tests/options_config_install_test/config/install/field.field.node.options_install_test.field_options_float.yml
new file mode 100644
index 0000000..581f2b7
--- /dev/null
+++ b/core/modules/options/tests/options_config_install_test/config/install/field.field.node.options_install_test.field_options_float.yml
@@ -0,0 +1,19 @@
+langcode: en
+status: true
+dependencies:
+  entity:
+    - field.storage.node.field_options_float
+    - node.type.options_install_test
+id: node.options_install_test.field_options_float
+field_name: field_options_float
+entity_type: node
+bundle: options_install_test
+label: field_options_float
+description: ''
+required: false
+translatable: true
+default_value: {  }
+default_value_callback: ''
+settings: {  }
+third_party_settings: {  }
+field_type: list_float
diff --git a/core/modules/options/tests/options_config_install_test/config/install/field.storage.node.field_options_float.yml b/core/modules/options/tests/options_config_install_test/config/install/field.storage.node.field_options_float.yml
new file mode 100644
index 0000000..daf5c75
--- /dev/null
+++ b/core/modules/options/tests/options_config_install_test/config/install/field.storage.node.field_options_float.yml
@@ -0,0 +1,24 @@
+langcode: en
+status: true
+dependencies:
+  module:
+    - node
+    - options
+id: node.field_options_float
+field_name: field_options_float
+entity_type: node
+type: list_float
+settings:
+  allowed_values:
+    -
+      value: 0
+      label: Zero
+    -
+      value: 0.5
+      label: 'Point five'
+  allowed_values_function: ''
+module: options
+locked: false
+cardinality: 1
+translatable: true
+indexes: {  }
diff --git a/core/modules/options/tests/options_config_install_test/config/install/node.type.options_install_test.yml b/core/modules/options/tests/options_config_install_test/config/install/node.type.options_install_test.yml
new file mode 100644
index 0000000..5d843bc
--- /dev/null
+++ b/core/modules/options/tests/options_config_install_test/config/install/node.type.options_install_test.yml
@@ -0,0 +1,11 @@
+langcode: en
+status: true
+dependencies: {  }
+name: options_install_test
+type: options_install_test
+description: null
+help: null
+new_revision: false
+preview_mode: 1
+display_submitted: true
+third_party_settings: {  }
diff --git a/core/modules/options/tests/options_test.info.yml b/core/modules/options/tests/options_config_install_test/options_config_install_test.info.yml
similarity index 62%
copy from core/modules/options/tests/options_test.info.yml
copy to core/modules/options/tests/options_config_install_test/options_config_install_test.info.yml
index add43a4..d9f4086 100644
--- a/core/modules/options/tests/options_test.info.yml
+++ b/core/modules/options/tests/options_config_install_test/options_config_install_test.info.yml
@@ -1,6 +1,9 @@
-name: 'Options test'
+name: 'Options config install test'
 type: module
 description: 'Support module for the Options module tests.'
 core: 8.x
 package: Testing
 version: VERSION
+dependencies:
+  - node
+  - options
diff --git a/core/modules/options/tests/options_test.info.yml b/core/modules/options/tests/options_test/options_test.info.yml
similarity index 100%
rename from core/modules/options/tests/options_test.info.yml
rename to core/modules/options/tests/options_test/options_test.info.yml
diff --git a/core/modules/options/tests/options_test.module b/core/modules/options/tests/options_test/options_test.module
similarity index 100%
rename from core/modules/options/tests/options_test.module
rename to core/modules/options/tests/options_test/options_test.module