diff --git a/markdown.php b/markdown.php
index 4be4c561..cb03d148 100644
--- a/markdown.php
+++ b/markdown.php
@@ -467,8 +467,8 @@ protected function build($str) {
 				'fence'=>'/^`{3}\h*(\w+)?.*?[^\n]*\n+(.+?)`{3}[^\n]*'.
 					'(?:\n+|$)/s',
 				'hr'=>'/^\h*[*_\-](?:\h?[\*_\-]){2,}\h*(?:\n+|$)/',
-				'atx'=>'/^\h*(#{1,6})\h?(.+?)\h*(?:#.*)?(?:\n+|$)/',
-				'setext'=>'/^\h*(.+?)\h*\n([=\-])+\h*(?:\n+|$)/',
+				'atx'=>'/^\h*(#{1,6})\h?(.+?)\h*(?:#.*)?(?:\n+|$)/u',
+				'setext'=>'/^\h*(.+?)\h*\n([=\-])+\h*(?:\n+|$)/u',
 				'li'=>'/^(?:(?:[*+\-]|\d+\.)\h.+?(?:\n+|$)'.
 					'(?:(?: {4}|\t)+.+?(?:\n+|$))*)+/s',
 				'raw'=>'/^((?:<!--.+?-->|'.