diff --git a/core/modules/system/lib/Drupal/system/Plugin/ImageToolkit/GDToolkit.php b/core/modules/system/lib/Drupal/system/Plugin/ImageToolkit/GDToolkit.php
index 1f6cef3..2d8544e 100644
--- a/core/modules/system/lib/Drupal/system/Plugin/ImageToolkit/GDToolkit.php
+++ b/core/modules/system/lib/Drupal/system/Plugin/ImageToolkit/GDToolkit.php
@@ -221,8 +221,17 @@ public function getInfo(ImageInterface $image) {
     $data = getimagesize($image->getSource());
 
     if (isset($data) && is_array($data)) {
-      $extension = image_type_to_extension($data[2], FALSE);
-      $extension = in_array($extension, self::getAvailableExtensions()) ? $extension : '';
+      // image_type_to_extension(IMAGETYPE_JPEG) always returns 'jpeg' event if
+      // the extension is 'jpg'. Extract the extension from the filename.
+      if ($data[2] == IMAGETYPE_JPEG) {
+        $extension = pathinfo($image->getSource(), PATHINFO_EXTENSION);
+        // It may be a temporary file, without extension. Fallback to 'jpg'.
+        $extension = in_array($extension, array('jpg', 'jpeg')) ? $extension : 'jpg';
+      }
+      else {
+        $extension = image_type_to_extension($data[2], FALSE);
+        $extension = in_array($extension, self::getAvailableExtensions()) ? $extension : '';
+      }
       $details = array(
         'width'     => $data[0],
         'height'    => $data[1],
diff --git a/core/modules/system/lib/Drupal/system/Tests/Image/ToolkitGdTest.php b/core/modules/system/lib/Drupal/system/Tests/Image/ToolkitGdTest.php
index 1797b78..6917942 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Image/ToolkitGdTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Image/ToolkitGdTest.php
@@ -264,7 +264,7 @@ function testManipulations() {
         $this->assertTrue($correct_dimensions_object, format_string('Image %file object after %action action is reporting the proper height and width values.', array('%file' => $file, '%action' => $op)));
 
         // JPEG colors will always be messed up due to compression.
-        if ($image->getExtension() != 'jpg') {
+        if (!in_array($image->getExtension(), array('jpg', 'jpeg'))) {
           // Now check each of the corners to ensure color correctness.
           foreach ($values['corners'] as $key => $corner) {
             // Get the location of the corner.
diff --git a/core/modules/system/tests/modules/image_test/lib/Drupal/image_test/Plugin/ImageToolkit/TestToolkit.php b/core/modules/system/tests/modules/image_test/lib/Drupal/image_test/Plugin/ImageToolkit/TestToolkit.php
index 60ef977..762288c 100644
--- a/core/modules/system/tests/modules/image_test/lib/Drupal/image_test/Plugin/ImageToolkit/TestToolkit.php
+++ b/core/modules/system/tests/modules/image_test/lib/Drupal/image_test/Plugin/ImageToolkit/TestToolkit.php
@@ -46,8 +46,17 @@ public function getInfo(ImageInterface $image) {
     $data = getimagesize($image->getSource());
 
     if (isset($data) && is_array($data)) {
-      $extension = image_type_to_extension($data[2], FALSE);
-      $extension = in_array($extension, self::getAvailableExtensions()) ? $extension : '';
+      // image_type_to_extension(IMAGETYPE_JPEG) always returns 'jpeg' event if
+      // the extension is 'jpg'. Extract the extension from the filename.
+      if ($data[2] == IMAGETYPE_JPEG) {
+        $extension = pathinfo($image->getSource(), PATHINFO_EXTENSION);
+        // It may be a temporary file, without extension. Fallback to 'jpg'.
+        $extension = in_array($extension, array('jpg', 'jpeg')) ? $extension : 'jpg';
+      }
+      else {
+        $extension = image_type_to_extension($data[2], FALSE);
+        $extension = in_array($extension, self::getAvailableExtensions()) ? $extension : '';
+      }
       $details = array(
         'width'     => $data[0],
         'height'    => $data[1],