diff --git a/modules/image/image.module b/modules/image/image.module
index a9c4d02..171c804 100644
--- a/modules/image/image.module
+++ b/modules/image/image.module
@@ -292,7 +292,7 @@ function image_file_download($uri) {
     if ($info = image_get_info($uri)) {
       // Check the permissions of the original to grant access to this image.
       $headers = module_invoke_all('file_download', $original_uri);
-      if (!in_array(-1, $headers)) {
+      if (!in_array(-1, $headers) && !empty($headers)) {
         return array(
           // Send headers describing the image's size, and MIME-type...
           'Content-Type' => $info['mime_type'],