diff --git a/core/modules/image/src/Tests/ImageFieldWidgetTest.php b/core/modules/image/src/Tests/ImageFieldWidgetTest.php
index 8bc70bc..252f4f7 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/Tests/Image/ToolkitGdTest.php b/core/modules/system/src/Tests/Image/ToolkitGdTest.php
index a731f5b..ef90e71 100644
--- a/core/modules/system/src/Tests/Image/ToolkitGdTest.php
+++ b/core/modules/system/src/Tests/Image/ToolkitGdTest.php
@@ -111,6 +111,11 @@ 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));
+
     // 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);