diff --git a/core/includes/bootstrap.inc b/core/includes/bootstrap.inc
index 8fa8a25..cf88394 100644
--- a/core/includes/bootstrap.inc
+++ b/core/includes/bootstrap.inc
@@ -1610,7 +1610,7 @@ function format_string($string, array $args = array()) {
  * @ingroup sanitization
  */
 function check_plain($text) {
-  return htmlspecialchars($text, ENT_QUOTES, 'UTF-8');
+  return htmlspecialchars($text, ENT_QUOTES | ENT_HTML5, 'UTF-8');
 }
 
 /**