diff --git a/picture.module b/picture.module
index dd27eec..92b6192 100644
--- a/picture.module
+++ b/picture.module
@@ -1043,6 +1043,13 @@ function theme_picture_formatter($variables) {
   if (isset($item['title']) && drupal_strlen($item['title']) != 0) {
     $responsive_image['#title'] = $item['title'];
   }
+  if (!empty($item['class'])) {
+    $class = (!empty($responsive_image['#attributes']['class'])) ? $responsive_image['#attributes']['class'] : array();
+    if (!is_array($class)) {
+      $class = array($class);
+    }
+    $responsive_image['#attributes']['class'] = $class + $item['class'];
+  }
   if (is_array($variables['path']) && isset($variables['path']['path'])) {
     $path = $variables['path']['path'];
     $options = isset($variables['path']['options']) ? $variables['path']['options'] : array();