diff --git a/scald_file.module b/scald_file.module
index 399fdd9..b5f228f 100644
--- a/scald_file.module
+++ b/scald_file.module
@@ -436,6 +436,31 @@ function scald_file_scald_render($atom, $context, $options = array()) {
 }
 
 /**
+ * Implements hook_action_info().
+ */
+function scald_file_action_info() {
+  return array(
+    'scald_file_generate_thumbnail' => array(
+      'type' => 'scald_atom',
+      'label' => t('Generate Thumbnail'),
+      'configurable' => FALSE,
+      'behavior' => array('changes_property'),
+      'triggers' => array('any'),
+    ),
+  );
+}
+
+/**
+ * Action callback for the thumbnail generation action.
+ */
+function scald_file_generate_thumbnail($entity, $context) {
+  if ($entity->provider === 'scald_file') {
+    $entity->data['scald_thumbnail_default'] = TRUE;
+    scald_atom_save($entity);
+  }
+}
+
+/**
  * Determines if a command exists on the current environment
  *
  * @param string $command The command to check