diff --git a/inline_entity_form.module b/inline_entity_form.module
index 60a9cdb..80ed5bb 100644
--- a/inline_entity_form.module
+++ b/inline_entity_form.module
@@ -1740,7 +1740,7 @@ function theme_inline_entity_form_entity_table($variables) {
         }
         $data = drupal_render($renderable_data);
       }
-      elseif ($field['type'] == 'callback' && isset($field['render_callback']) && function_exists($field['render_callback'])) {
+      elseif ($field['type'] == 'callback' && isset($field['render_callback']) && is_callable($field['render_callback'])) {
         $data = call_user_func($field['render_callback'], $entity_type, $entity);
       }