diff --git a/core/modules/image/image.field.inc b/core/modules/image/image.field.inc
index aef6be7..45ade62 100644
--- a/core/modules/image/image.field.inc
+++ b/core/modules/image/image.field.inc
@@ -578,7 +578,7 @@ function theme_image_formatter($variables) {
   $item = $variables['item'];
 
   // Do not output an empty 'title' attribute.
-  if (drupal_strlen($item['title']) == 0) {
+  if (isset($item['title']) && drupal_strlen($item['title']) == 0) {
     unset($item['title']);
   }