diff -u b/core/modules/image/lib/Drupal/image/Tests/ImageThemeFunctionTest.php b/core/modules/image/lib/Drupal/image/Tests/ImageThemeFunctionTest.php
--- b/core/modules/image/lib/Drupal/image/Tests/ImageThemeFunctionTest.php
+++ b/core/modules/image/lib/Drupal/image/Tests/ImageThemeFunctionTest.php
@@ -57,7 +57,7 @@
       ),
     );
     $rendered_element = render($element);
-    $expected_result = '<a href="' . base_path() . $path . '"><img class="image-style-test" src="' . $url . ' /></a>';
+    $expected_result = '<a href="' . base_path() . $path . '"><img class="image-style-test" src="' . $url . '" /></a>';
     $this->assertEqual($expected_result, $rendered_element, 'theme_image_formatter() correctly renders with a NULL value for the alt option.');
 
     // Test using theme_image_formatter() without an image title, alt text, or
@@ -106,7 +106,7 @@
     // Test using theme_image_style() with a NULL value for the alt option.
     $element['alt'] = NULL;
     $rendered_element = render($element);
-    $expected_result = '<img class="image-style-image-test" src="' . $url . ' />';
+    $expected_result = '<img class="image-style-image-test" src="' . $url . '" />';
     $this->assertEqual($expected_result, $rendered_element, 'theme_image_style() renders an image correctly with a NULL value for the alt option.');
   }