diff --git a/core/modules/image/image.install b/core/modules/image/image.install
index 75ffd2a..3b357fa 100644
--- a/core/modules/image/image.install
+++ b/core/modules/image/image.install
@@ -5,6 +5,8 @@
  * Install, update and uninstall functions for the image module.
  */
 
+use Drupal\Component\Uuid\Uuid;
+
 /**
  * Implements hook_install().
  */
@@ -103,3 +105,68 @@ function image_requirements($phase) {
 
   return $requirements;
 }
+
+/**
+ * Loads all effects for an image style.
+ *
+ * @param array $style
+ *   The image style (array) to retrieve effects for.
+ *
+ * @return array
+ *   An array of effects keyed by UUIDs.
+ *
+ * @see image_update_8000()
+ */
+function _image_update_get_style_with_effects(array $style) {
+  // Retrieve image effects.
+  // @todo Module updates are not able to invoke module hooks and API functions;
+  //   additional information previously supplied via hook_image_effect_info()
+  //   is not and cannot be taken into account.
+  $effects = array();
+  $result = db_select('image_effects', NULL, array('fetch' => PDO::FETCH_ASSOC))
+    ->fields('image_effects')
+    ->condition('isid', $style['isid'])
+    ->execute();
+  foreach ($result as $effect) {
+    unset($effect['isid']);
+    $effect['data'] = unserialize($effect['data']);
+
+    // Generate a unique image effect ID for the effect.
+    $uuid = new Uuid();
+    $effect['ieid'] = $uuid->generate();
+
+    $effects[$effect['ieid']] = $effect;
+  }
+  return $effects;
+}
+
+/**
+ * Convert existing image styles to the new config system.
+ */
+function image_update_8000() {
+  $styles = array();
+  $result = db_select('image_styles', NULL, array('fetch' => PDO::FETCH_ASSOC))
+    ->fields('image_styles')
+    ->execute()
+    ->fetchAllAssoc('name', PDO::FETCH_ASSOC);
+  foreach ($result as $style_name => $style) {
+    $style['effects'] = _image_update_get_style_with_effects($style);
+    $styles[$style_name] = $style;
+  }
+
+  // Convert each style into a configuration object.
+  foreach ($styles as $name => $style) {
+    $config = config('image.style.' . $name);
+    $config->set('name', $name);
+    $config->set('effects', $style['effects']);
+    $config->save();
+  }
+}
+
+/**
+ * Remove the {image_styles} and {image_effects} tables.
+ */
+function image_update_8001() {
+  db_drop_table('image_styles');
+  db_drop_table('image_effects');
+}
diff --git a/core/modules/system/lib/Drupal/system/Tests/Upgrade/ImageUpgradePathTest.php b/core/modules/system/lib/Drupal/system/Tests/Upgrade/ImageUpgradePathTest.php
new file mode 100644
index 0000000..d0e9951
--- /dev/null
+++ b/core/modules/system/lib/Drupal/system/Tests/Upgrade/ImageUpgradePathTest.php
@@ -0,0 +1,112 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\system\Tests\Upgrade\ImageUpgradePathTest.
+ */
+
+namespace Drupal\system\Tests\Upgrade;
+
+/**
+ * Test upgrade of overridden and custom image styles.
+ */
+class ImageUpgradePathTest extends UpgradePathTestBase {
+  public static function getInfo() {
+    return array(
+      'name' => 'Image upgrade test',
+      'description' => 'Upgrade tests for overridden and custom image styles.',
+      'group' => 'Upgrade path',
+    );
+  }
+
+  public function setUp() {
+    $this->databaseDumpFiles = array(
+      drupal_get_path('module', 'system') . '/tests/upgrade/drupal-7.bare.standard_all.database.php.gz',
+      drupal_get_path('module', 'system') . '/tests/upgrade/drupal-7.image.database.php',
+    );
+    parent::setUp();
+  }
+
+  /**
+   * Tests that custom and overridden image styles have been upgraded.
+   */
+  public function testImageStyleUpgrade() {
+    $this->assertTrue($this->performUpgrade(), 'The upgrade was completed successfully.');
+
+    // Verify that image styles were properly upgraded.
+    $expected_styles['test-custom'] = array(
+      'name' => 'test-custom',
+      'effects' => array(
+        'uuid1' => array(
+          'name' => 'image_rotate',
+          'data' => array(
+            'degrees' => '90',
+            'bgcolor' => '#FFFFFF',
+            'random' => '1',
+          ),
+          'weight' => '1',
+        ),
+        'uuid2' => array(
+          'name' => 'image_desaturate',
+          'data' => array(),
+          'weight' => '2',
+        ),
+      ),
+    );
+    $expected_styles['thumbnail'] = array(
+      'name' => 'thumbnail',
+      'effects' => array (
+        'uuid1' => array(
+          'name' => 'image_scale',
+          'data' => array (
+            'width' => '177',
+            'height' => '177',
+            'upscale' => '0',
+          ),
+          'weight' => '0',
+        ),
+      ),
+    );
+    foreach ($expected_styles as $name => $style) {
+      $config = config('image.style.' . $name);
+      // Replace placeholder uuid + number keys with UUID's generated during by
+      // the image style upgrade functions.
+      $count = 1;
+      foreach ($config->get('effects') as $uuid => $effect) {
+        // Copy placeholder data.
+        $style['effects'][$uuid] = $style['effects']['uuid' . $count];
+        // Set the missing ieid key as this is unknown because it is a UUID.
+        $style['effects'][$uuid]['ieid'] = $uuid;
+        // Remove the placeholder data.
+        unset($style['effects']['uuid' . $count]);
+        $count++;
+      }
+      $this->assertEqual($this->sortByKey($style), $config->get(), format_string('@first is equal to @second.', array(
+        '@first' => var_export($this->sortByKey($style), TRUE),
+        '@second' => var_export($config->get(), TRUE),
+      )));
+    }
+  }
+  /**
+   * Sorts all keys in configuration data.
+   *
+   * Since we can not be sure of the order of the UUID's generated by
+   * _image_update_get_style_with_effects() we need to sort the data in order
+   * to compare it with data saved in the config system.
+   *
+   * @param array $data
+   *   An associative array to sort recursively by key name.
+   *
+   * @return array
+   *   A sorted array.
+   */
+  public function sortByKey(array $data) {
+    ksort($data);
+    foreach ($data as &$value) {
+      if (is_array($value)) {
+        $this->sortByKey($value);
+      }
+    }
+    return $data;
+  }
+}
\ No newline at end of file
diff --git a/core/modules/system/tests/upgrade/drupal-7.image.database.php b/core/modules/system/tests/upgrade/drupal-7.image.database.php
new file mode 100644
index 0000000..6d7f456
--- /dev/null
+++ b/core/modules/system/tests/upgrade/drupal-7.image.database.php
@@ -0,0 +1,59 @@
+<?php
+
+/**
+ * @file
+ * Database additions for language tests. Used in upgrade.language.test.
+ *
+ * This dump only contains data and schema components relevant for language
+ * functionality. The drupal-7.filled.database.php file is imported before
+ * this dump, so the two form the database structure expected in tests
+ * altogether.
+ */
+
+// Add image styles.
+db_insert('image_styles')->fields(array(
+  'isid',
+  'name',
+))
+// Override thumbnail style.
+->values(array(
+  'isid' => '1',
+  'name' => 'thumbnail',
+))
+// Custom style.
+->values(array(
+  'isid' => '2',
+  'name' => 'test-custom',
+))
+->execute();
+
+// Add image effects.
+db_insert('image_effects')->fields(array(
+  'ieid',
+  'isid',
+  'weight',
+  'name',
+  'data',
+))
+->values(array(
+  'ieid' => '1',
+  'isid' => '1',
+  'weight' => '0',
+  'name' => 'image_scale',
+  'data' => 'a:3:{s:5:"width";s:3:"177";s:6:"height";s:3:"177";s:7:"upscale";i:0;}',
+))
+->values(array(
+  'ieid' => '3',
+  'isid' => '2',
+  'weight' => '1',
+  'name' => 'image_rotate',
+  'data' => 'a:3:{s:7:"degrees";s:2:"90";s:7:"bgcolor";s:7:"#FFFFFF";s:6:"random";i:1;}',
+))
+->values(array(
+  'ieid' => '4',
+  'isid' => '2',
+  'weight' => '2',
+  'name' => 'image_desaturate',
+  'data' => 'a:0:{}',
+))
+->execute();