diff --git a/formatter_field.module b/formatter_field.module
index a844da3..93ac8d1 100644
--- a/formatter_field.module
+++ b/formatter_field.module
@@ -220,3 +220,22 @@ function formatter_field_field_formatter_view($entity_type, $entity, $field, $in
   return $element;
 }
 
+/**
+ * Implements hook_preprocess_field().
+ */
+function formatter_field_preprocess_field(&$variables) {
+  $instances = field_read_instances(array(
+    'entity_type' => $variables['element']['#entity_type'],
+    'bundle' => $variables['element']['#bundle'],
+  ));
+  foreach ($instances as $formatter_instance) {
+    if ($formatter_instance['widget']['module'] == 'formatter_field' && $formatter_instance['settings']['field_name'] == $variables['element']['#field_name']) {
+      $formatter_items = field_get_items($variables['element']['#entity_type'], $variables['element']['#object'], $formatter_instance['field_name']);
+      $display = $formatter_items[0];
+      if (is_string($display['settings'])) {
+        $display['settings'] = unserialize($display['settings']);
+      }
+      $variables['classes_array'][] = str_replace('_', '-', $display['settings']['file_view_mode']);
+    }
+  }
+}