diff --git a/inc/functions.php b/inc/functions.php
index 1b77c191..ade92cbd 100644
--- a/inc/functions.php
+++ b/inc/functions.php
@@ -2138,14 +2138,14 @@ function rrmdir($dir) {
 	}
 }
 
-function poster_id($ip, $thread) {
+function poster_id($ip, $thread, $board) {
 	global $config;
 
-	if ($id = event('poster-id', $ip, $thread))
+	if ($id = event('poster-id', $ip, $thread, $board))
 		return $id;
 
 	// Confusing, hard to brute-force, but simple algorithm
-	return substr(sha1(sha1($ip . $config['secure_trip_salt'] . $thread) . $config['secure_trip_salt']), 0, $config['poster_id_length']);
+	return substr(sha1(sha1($ip . $config['secure_trip_salt'] . $thread . $board) . $config['secure_trip_salt']), 0, $config['poster_id_length']);
 }
 
 function generate_tripcode($name) {
diff --git a/inc/lib/Twig/Extensions/Extension/Tinyboard.php b/inc/lib/Twig/Extensions/Extension/Tinyboard.php
index 81276147..75af6890 100644
--- a/inc/lib/Twig/Extensions/Extension/Tinyboard.php
+++ b/inc/lib/Twig/Extensions/Extension/Tinyboard.php
@@ -19,7 +19,6 @@ class Twig_Extensions_Extension_Tinyboard extends Twig_Extension
 			new Twig_SimpleFilter('capcode', 'capcode'),
 			new Twig_SimpleFilter('hasPermission', 'twig_hasPermission_filter'),
 			new Twig_SimpleFilter('date', 'twig_date_filter'),
-			new Twig_SimpleFilter('poster_id', 'poster_id'),
 			new Twig_SimpleFilter('remove_whitespace', 'twig_remove_whitespace_filter'),
 			new Twig_SimpleFilter('count', 'count'),
 			new Twig_SimpleFilter('ago', 'ago'),
@@ -40,6 +39,7 @@ class Twig_Extensions_Extension_Tinyboard extends Twig_Extension
 		return array(
 			new Twig_SimpleFunction('time', 'time'),
 			new Twig_SimpleFunction('floor', 'floor'),
+			new Twig_SimpleFunction('poster_id', 'poster_id'),
 			new Twig_SimpleFunction('timezone', 'twig_timezone_function'),
 			new Twig_SimpleFunction('hiddenInputs', 'hiddenInputs'),
 			new Twig_SimpleFunction('hiddenInputsHash', 'hiddenInputsHash'),
diff --git a/templates/post/poster_id.html b/templates/post/poster_id.html
index 4efc56ff..3f5ba798 100644
--- a/templates/post/poster_id.html
+++ b/templates/post/poster_id.html
@@ -1,7 +1,7 @@
 {% if config.poster_ids %}
 	{% if post.thread %}
-		 ID: <span class="poster_id">{{ post.ip|poster_id(post.thread) }}</span>
+		 ID: <span class="poster_id">{{ poster_id(post.ip, post.thread, board.uri) }}</span>
 	{% else %}
-		 ID: <span class="poster_id">{{ post.ip|poster_id(post.id) }}</span>
+		 ID: <span class="poster_id">{{ poster_id(post.ip, post.id, board.uri) }}</span>
 	{% endif %}
 {% endif %}