diff --git a/extensions/mentions/src/UserMentionsParser.php b/extensions/mentions/src/UserMentionsParser.php
index f499e7c24..51c463162 100644
--- a/extensions/mentions/src/UserMentionsParser.php
+++ b/extensions/mentions/src/UserMentionsParser.php
@@ -2,5 +2,5 @@
 
 class UserMentionsParser extends MentionsParserAbstract
 {
-    protected $pattern = '/\B@(?P<username>[a-z0-9_-]+)\b/i';
+    protected $pattern = '/\B@(?P<username>[a-z0-9_-]+)(?!#)/i';
 }