diff --git a/core/modules/responsive_image/responsive_image.module b/core/modules/responsive_image/responsive_image.module
index ec4dbe1..f3fc585 100644
--- a/core/modules/responsive_image/responsive_image.module
+++ b/core/modules/responsive_image/responsive_image.module
@@ -18,6 +18,7 @@
  * The machine name for the empty image breakpoint image style option.
  */
 const RESPONSIVE_IMAGE_EMPTY_IMAGE = '_empty image_';
+const RESPONSIVE_IMAGE_ORIGINAL_IMAGE = '_original image_';
 
 /**
  * Implements hook_help().
@@ -456,7 +457,12 @@ function responsive_image_get_mime_type($image_style_name, $extension) {
   }
   // The MIME type guesser needs a full path, not just an extension, but the
   // file doesn't have to exist.
-  $fake_path = 'responsive_image.' . ImageStyle::load($image_style_name)->getDerivativeExtension($extension);
+  if ($image_style_name == RESPONSIVE_IMAGE_ORIGINAL_IMAGE) {
+    $fake_path = 'responsive_image.' . $extension;
+  }
+  else {
+    $fake_path = 'responsive_image.' . ImageStyle::load($image_style_name)->getDerivativeExtension($extension);
+  }
   return Drupal::service('file.mime_type.guesser.extension')->guess($fake_path);
 }
 
diff --git a/core/modules/responsive_image/src/ResponsiveImageStyleForm.php b/core/modules/responsive_image/src/ResponsiveImageStyleForm.php
index 9e10fe9..fbf892a 100644
--- a/core/modules/responsive_image/src/ResponsiveImageStyleForm.php
+++ b/core/modules/responsive_image/src/ResponsiveImageStyleForm.php
@@ -84,6 +84,7 @@ public function form(array $form, FormStateInterface $form_state) {
     );
 
     $image_styles = image_style_options(TRUE);
+    $image_styles[RESPONSIVE_IMAGE_ORIGINAL_IMAGE]=  t('- None (original image) -');
     $image_styles[RESPONSIVE_IMAGE_EMPTY_IMAGE] = $this->t('- empty image -');
 
     if ((bool) $responsive_image_style->id() && $this->operation != 'duplicate') {
diff --git a/core/modules/responsive_image/tests/src/Unit/ResponsiveImageStyleConfigEntityUnitTest.php b/core/modules/responsive_image/tests/src/Unit/ResponsiveImageStyleConfigEntityUnitTest.php
index 63580a8..f019c35 100644
--- a/core/modules/responsive_image/tests/src/Unit/ResponsiveImageStyleConfigEntityUnitTest.php
+++ b/core/modules/responsive_image/tests/src/Unit/ResponsiveImageStyleConfigEntityUnitTest.php
@@ -208,6 +208,10 @@ public function testGetKeyedImageStyleMappings() {
       'image_mapping_type' => 'image_style',
       'image_mapping' => 'thumbnail',
     ));
+    $entity->addImageStyleMapping('test_breakpoint2', '2x', array(
+      'image_mapping_type' => 'image_style',
+      'image_mapping' => '_original image_',
+    ));
 
     $expected = array(
       'test_breakpoint' => array(
@@ -236,6 +240,12 @@ public function testGetKeyedImageStyleMappings() {
           'image_mapping_type' => 'image_style',
           'image_mapping' => 'thumbnail',
         ),
+        '2x' => array(
+          'breakpoint_id' => 'test_breakpoint2',
+          'multiplier' => '2x',
+          'image_mapping_type' => 'image_style',
+          'image_mapping' => '_original image_',
+        ),
       )
     );
     $this->assertEquals($expected, $entity->getKeyedImageStyleMappings());