diff --git a/core/modules/image/src/Plugin/Field/FieldWidget/ImageWidget.php b/core/modules/image/src/Plugin/Field/FieldWidget/ImageWidget.php
index 82092e6..0b52735 100644
--- a/core/modules/image/src/Plugin/Field/FieldWidget/ImageWidget.php
+++ b/core/modules/image/src/Plugin/Field/FieldWidget/ImageWidget.php
@@ -7,8 +7,8 @@
 
 namespace Drupal\image\Plugin\Field\FieldWidget;
 
-use Drupal\Core\Field\FieldItemListInterface;
 use Drupal\Component\Utility\NestedArray;
+use Drupal\Core\Field\FieldItemListInterface;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\file\Entity\File;
 use Drupal\file\Plugin\Field\FieldWidget\FileWidget;
@@ -27,6 +27,13 @@
 class ImageWidget extends FileWidget {
 
   /**
+   * The image factory service.
+   *
+   * @var \Drupal\Core\Image\ImageFactory
+   */
+  protected $imageFactory;
+
+  /**
    * {@inheritdoc}
    */
   public static function defaultSettings() {
@@ -121,11 +128,17 @@ public function formElement(FieldItemListInterface $items, $delta, array $elemen
       $element['#upload_validators']['file_validate_image_resolution'] = array($field_settings['max_resolution'], $field_settings['min_resolution']);
     }
 
-    // If not using custom extension validation, ensure this is an image.
-    $supported_extensions = array('png', 'gif', 'jpg', 'jpeg');
-    $extensions = isset($element['#upload_validators']['file_validate_extensions'][0]) ? $element['#upload_validators']['file_validate_extensions'][0] : implode(' ', $supported_extensions);
-    $extensions = array_intersect(explode(' ', $extensions), $supported_extensions);
-    $element['#upload_validators']['file_validate_extensions'][0] = implode(' ', $extensions);
+    // If using custom extension validation, ensure that the extensions are
+    // supported by the current image toolkit.
+    $supported_extensions = $this->getImageFactory()->getSupportedExtensions();
+    if (isset($element['#upload_validators']['file_validate_extensions'][0])) {
+      $extensions = $element['#upload_validators']['file_validate_extensions'][0];
+      $extensions = array_intersect(explode(' ', $extensions), $supported_extensions);
+      $element['#upload_validators']['file_validate_extensions'][0] = implode(' ', $extensions);
+    }
+    else {
+      $element['#upload_validators']['file_validate_extensions'][0] = implode(' ', $supported_extensions);
+    }
 
     // Add properties needed by process() method.
     $element['#preview_image_style'] = $this->getSetting('preview_image_style');
@@ -273,4 +286,23 @@ public static function validateRequiredFields($element, FormStateInterface $form
     }
   }
 
+  /**
+   * Returns the image factory service.
+   *
+   * @deprecated in Drupal 8.0.x, will be removed before Drupal 9.0.0.
+   *
+   * @return \Drupal\Core\Image\ImageFactory
+   *   The image factory service.
+   *
+   * @internal
+   *
+   * @todo Replace this method with proper service injection in 9.0.x.
+   */
+  protected function getImageFactory() {
+    if (!$this->imageFactory) {
+      $this->imageFactory = \Drupal::service('image.factory');
+    }
+    return $this->imageFactory;
+  }
+
 }
diff --git a/core/modules/image/src/Tests/ImageFieldWidgetTest.php b/core/modules/image/src/Tests/ImageFieldWidgetTest.php
index 8bc70bc..0f027ab 100644
--- a/core/modules/image/src/Tests/ImageFieldWidgetTest.php
+++ b/core/modules/image/src/Tests/ImageFieldWidgetTest.php
@@ -7,6 +7,8 @@
 
 namespace Drupal\image\Tests;
 
+use Drupal\field\Entity\FieldConfig;
+
 /**
  * Tests the image field widget.
  *
@@ -30,6 +32,22 @@ public function testWidgetElement() {
     $this->createImageField($field_name, 'article', array(), $field_settings);
     $this->drupalGet('node/add/article');
     $this->assertNotEqual(0, count($this->xpath('//div[contains(@class, "field--widget-image-image")]')), 'Image field widget found on add/node page', 'Browser');
+
+    // Check for allowed image file extensions - default.
+    $this->assertText('Allowed types: png gif jpg jpeg.');
+
+    // Try adding to the field config an unsupported extension, should not
+    // appear in the allowed types.
+    $field_config = FieldConfig::loadByName('node', 'article', $field_name);
+    $field_config->setSetting('file_extensions', 'png gif jpg jpeg tiff')->save();
+    $this->drupalGet('node/add/article');
+    $this->assertText('Allowed types: png gif jpg jpeg.');
+
+    // Add a supported extension and remove some supported ones, we should see
+    // the intersect of those entered in field config with those supported.
+    $field_config->setSetting('file_extensions', 'png jpe tiff')->save();
+    $this->drupalGet('node/add/article');
+    $this->assertText('Allowed types: png jpe.');
   }
 
 }
diff --git a/core/modules/system/src/Plugin/ImageToolkit/GDToolkit.php b/core/modules/system/src/Plugin/ImageToolkit/GDToolkit.php
index f9cfb53..d9f4a09 100644
--- a/core/modules/system/src/Plugin/ImageToolkit/GDToolkit.php
+++ b/core/modules/system/src/Plugin/ImageToolkit/GDToolkit.php
@@ -398,7 +398,15 @@ public static function isAvailable() {
   public static function getSupportedExtensions() {
     $extensions = array();
     foreach (static::supportedTypes() as $image_type) {
-      $extensions[] = Unicode::strtolower(image_type_to_extension($image_type, FALSE));
+      // @todo Automatically fetch possible extensions for each mime type.
+      // @see https://www.drupal.org/node/2311679
+      $extension = Unicode::strtolower(image_type_to_extension($image_type, FALSE));
+      $extensions[] = $extension;
+      // Add some known similar extensions.
+      if ($extension === 'jpeg') {
+        $extensions[] = 'jpg';
+        $extensions[] = 'jpe';
+      }
     }
     return $extensions;
   }
@@ -418,6 +426,9 @@ public static function getSupportedExtensions() {
    * @see image_type_to_extension()
    */
   public function extensionToImageType($extension) {
+    if (in_array($extension, ['jpe', 'jpg'])) {
+      $extension = 'jpeg';
+    }
     foreach ($this->supportedTypes() as $type) {
       if (image_type_to_extension($type, FALSE) === $extension) {
         return $type;
diff --git a/core/modules/system/src/Tests/Image/ToolkitGdTest.php b/core/modules/system/src/Tests/Image/ToolkitGdTest.php
index a731f5b..9390cfc 100644
--- a/core/modules/system/src/Tests/Image/ToolkitGdTest.php
+++ b/core/modules/system/src/Tests/Image/ToolkitGdTest.php
@@ -111,6 +111,26 @@ function testManipulations() {
     // Test that the image factory is set to use the GD toolkit.
     $this->assertEqual($this->imageFactory->getToolkitId(), 'gd', 'The image factory is set to use the \'gd\' image toolkit.');
 
+    // Test the list of supported extensions.
+    $expected_extensions = ['png', 'gif', 'jpeg', 'jpg', 'jpe'];
+    $supported_extensions = $this->imageFactory->getSupportedExtensions();
+    $this->assertEqual($expected_extensions, array_intersect($expected_extensions, $supported_extensions));
+
+    // Test that the supported extensions map to correct internal GD image
+    // types.
+    $expected_image_types = [
+      'png' => IMAGETYPE_PNG,
+      'gif' => IMAGETYPE_GIF,
+      'jpeg' => IMAGETYPE_JPEG,
+      'jpg' => IMAGETYPE_JPEG,
+      'jpe' => IMAGETYPE_JPEG
+    ];
+    $image = $this->imageFactory->get();
+    foreach ($expected_image_types as $extension => $expected_image_type) {
+      $image_type = $image->getToolkit()->extensionToImageType($extension);
+      $this->assertEqual($expected_image_type, $image_type);
+    }
+
     // Typically the corner colors will be unchanged. These colors are in the
     // order of top-left, top-right, bottom-right, bottom-left.
     $default_corners = array($this->red, $this->green, $this->blue, $this->transparent);