diff --git a/activitypub.php b/activitypub.php
index b05f8b9..290e79e 100644
--- a/activitypub.php
+++ b/activitypub.php
@@ -19,7 +19,7 @@ namespace Activitypub;
  * Initialize plugin
  */
 function init() {
-	\defined( 'ACTIVITYPUB_HASHTAGS_REGEXP' ) || \define( 'ACTIVITYPUB_HASHTAGS_REGEXP', '(?:(?<=\s)|^)#(\w*[A-Za-z_]+\w*)' );
+	\defined( 'ACTIVITYPUB_HASHTAGS_REGEXP' ) || \define( 'ACTIVITYPUB_HASHTAGS_REGEXP', '(?:(?<=\s)|^)#([A-Za-z0-9_]+)(?:(?=\s|[[:punct:]]))' );
 	\defined( 'ACTIVITYPUB_ALLOWED_HTML' ) || \define( 'ACTIVITYPUB_ALLOWED_HTML', '<strong><a><p><ul><ol><li><code><blockquote><pre><img>' );
 	\defined( 'ACTIVITYPUB_CUSTOM_POST_CONTENT' ) || \define( 'ACTIVITYPUB_CUSTOM_POST_CONTENT', "<p><strong>%title%</strong></p>\n\n%content%\n\n<p>%hashtags%</p>\n\n<p>%shortlink%</p>" );
 	\defined( 'ACTIVITYPUB_PLUGIN' ) || \define( 'ACTIVITYPUB_PLUGIN', __FILE__ );