diff --git a/lib/rehype-sn.js b/lib/rehype-sn.js
index d65b3f7c..98a17dbd 100644
--- a/lib/rehype-sn.js
+++ b/lib/rehype-sn.js
@@ -6,7 +6,7 @@ import { toString } from 'mdast-util-to-string'
 const userGroup = '[\\w_]+'
 const subGroup = '[A-Za-z][\\w_]+'
 
-const mentionRegex = new RegExp('@(' + userGroup + '(?:\\/' + userGroup + ')?)', 'gi')
+const mentionRegex = new RegExp('(?:^|\\s)@(' + userGroup + '(?:\\/' + userGroup + ')?)', 'gi')
 const subRegex = new RegExp('~(' + subGroup + '(?:\\/' + subGroup + ')?)', 'gi')
 const nostrIdRegex = /\b((npub1|nevent1|nprofile1|note1|naddr1)[02-9ac-hj-np-z]+)\b/g