diff --git a/classes/Notice.php b/classes/Notice.php
index c9cca8a969..a640919094 100644
--- a/classes/Notice.php
+++ b/classes/Notice.php
@@ -153,7 +153,7 @@ class Notice extends Memcached_DataObject
     function saveTags()
     {
         /* extract all #hastags */
-        $count = preg_match_all('/(?:^|\s)#([\pL\pN_\-\.]{1,64})/', strtolower($this->content), $match);
+        $count = preg_match_all('/(?:^|\s)#([\pL\pN_\-\.]{1,64})/u', strtolower($this->content), $match);
         if (!$count) {
             return true;
         }
diff --git a/lib/util.php b/lib/util.php
index 85f49e4c59..b710a4391b 100644
--- a/lib/util.php
+++ b/lib/util.php
@@ -784,7 +784,7 @@ function common_render_text($text)
 
     $r = preg_replace('/[\x{0}-\x{8}\x{b}-\x{c}\x{e}-\x{19}]/', '', $r);
     $r = common_replace_urls_callback($r, 'common_linkify');
-    $r = preg_replace('/(^|\&quot\;|\'|\(|\[|\{|\s+)#([\pL\pN_\-\.]{1,64})/e', "'\\1#'.common_tag_link('\\2')", $r);
+    $r = preg_replace('/(^|\&quot\;|\'|\(|\[|\{|\s+)#([\pL\pN_\-\.]{1,64})/ue', "'\\1#'.common_tag_link('\\2')", $r);
     // XXX: machine tags
     return $r;
 }