diff --git a/modules/image/image.admin.inc b/modules/image/image.admin.inc
index cebe8940d3..dbeeaabf2a 100644
--- a/modules/image/image.admin.inc
+++ b/modules/image/image.admin.inc
@@ -821,11 +821,12 @@ function theme_image_style_preview($variables) {
   $output .= '</div>'; // End preview-image-wrapper.
 
   // Build the preview of the image style.
-  $preview_url = file_create_url($preview_file) . '?cache_bypass=' . REQUEST_TIME;
+  $token = IMAGE_DERIVATIVE_TOKEN . '=' . image_style_path_token($style['name'], file_default_scheme() . '://' . $sample_image);
+  $preview_url = file_create_url($preview_file) . '?cache_bypass=' . REQUEST_TIME . '&amp;' . $token;
   $output .= '<div class="preview-image-wrapper">';
-  $output .= check_plain($style['label']) . ' (' . l(t('view actual size'), file_create_url($preview_file) . '?' . time()) . ')';
+  $output .= check_plain($style['label']) . ' (' . l(t('view actual size'), file_create_url($preview_file) . '?' . time() . '&amp;' . $token) . ')';
   $output .= '<div class="preview-image modified-image" style="' . $preview_attributes['style'] . '">';
-  $output .= '<a href="' . file_create_url($preview_file) . '?' . time() . '">' . theme('image', array('path' => $preview_url, 'alt' => t('Sample modified image'), 'title' => '', 'attributes' => $preview_attributes)) . '</a>';
+  $output .= '<a href="' . file_create_url($preview_file) . '?' . time() . '&amp;' . $token . '">' . theme('image', array('path' => $preview_url, 'alt' => t('Sample modified image'), 'title' => '', 'attributes' => $preview_attributes)) . '</a>';
   $output .= '<div class="height" style="height: ' . $preview_height . 'px"><span>' . $preview_image['height'] . 'px</span></div>';
   $output .= '<div class="width" style="width: ' . $preview_width . 'px"><span>' . $preview_image['width'] . 'px</span></div>';
   $output .= '</div>'; // End preview-image.
diff --git a/modules/image/image.module b/modules/image/image.module
index dab88361a2..3700ac43cb 100644
--- a/modules/image/image.module
+++ b/modules/image/image.module
@@ -290,9 +290,12 @@ function image_file_download($uri) {
     // Remove the scheme from the path.
     array_shift($args);
 
+    // The remaining path for checks later on.
+    $remaining_path = implode('/', $args);
     // Then the remaining parts are the path to the image.
-    $original_uri = file_uri_scheme($uri) . '://' . implode('/', $args);
-
+    $original_uri = file_uri_scheme($uri) . '://' . $remaining_path;
+    // Grab the path to the sample image.
+    $sample_image = variable_get('image_style_preview_image', drupal_get_path('module', 'image') . '/sample.png');
     // Check that the file exists and is an image.
     if ($info = image_get_info($uri)) {
       // Check the permissions of the original to grant access to this image.
@@ -308,6 +311,19 @@ function image_file_download($uri) {
           // browser caching of private images.
         );
       }
+      // It's unlikely that a module would deny access to the sample image, but
+      // check the headers just in case. If no modules deny access, then grant
+      // access to the sample image by default.
+      elseif (empty($headers) && $remaining_path == $sample_image) {
+        return array(
+          // Send headers describing the image's size, and MIME-type...
+          'Content-Type' => $info['mime_type'],
+          'Content-Length' => $info['file_size'],
+          // By not explicitly setting them here, this uses normal Drupal
+          // Expires, Cache-Control and ETag headers to prevent proxy or
+          // browser caching of private images.
+        );
+      }
     }
     return -1;
   }