diff --git link.module link.module
index 98c8b3a..c862795 100644
--- link.module
+++ link.module
@@ -232,7 +232,7 @@ function link_field_validate($entity_type, $entity, $field, $instance, $langcode
     }
   }

-  if ($instance['settings']['url'] == 'optional' && $instance['settings']['title'] == 'optional' && $instance['required'] && !$optional_field_found) {
+  if ($instance['settings']['url'] === 'optional' && $instance['settings']['title'] === 'optional' && $instance['required'] && !$optional_field_found) {
     form_set_error($field['field_name'] .'][0][title', t('At least one title or URL must be entered.'));
   }
 }