diff --git a/modules/image/image.module b/modules/image/image.module
index fac8de9..9928ecf 100644
--- a/modules/image/image.module
+++ b/modules/image/image.module
@@ -839,6 +839,9 @@ function image_style_deliver($style, $scheme) {
       }
       if (count($headers)) {
         foreach ($headers as $name => $value) {
+          if (is_array($value)) {
+            $value = array_pop($value);
+          }
           drupal_add_http_header($name, $value);
         }
       }