diff --git a/phpBB/docs/CHANGELOG.html b/phpBB/docs/CHANGELOG.html
index 21fbeff610..0e6814d394 100644
--- a/phpBB/docs/CHANGELOG.html
+++ b/phpBB/docs/CHANGELOG.html
@@ -105,6 +105,7 @@
 		<li>[Change] Performance increase for format_date() (Bug #37575 - Patch by BartVB)</li>
 		<li>[Change] Changed prosilver date separator from 'on' to '&raquo;'</li>
 		<li>[Change] Performance increase for get_username_string() (Bug #37545 - Patch by BartVB)</li>
+		<li>[Change] Slight performance increase for common parameter calls to append_sid() (Bug #37555 - Patch by BartVB)</li>
 		<li>[Feature] Added 'AGO' setting to relative date strings. For example: posted 14 minutes ago. (Patch by BartVB)</li>
 	</ul>
 
diff --git a/phpBB/includes/functions.php b/phpBB/includes/functions.php
index f92b4f91ab..3ed71add61 100644
--- a/phpBB/includes/functions.php
+++ b/phpBB/includes/functions.php
@@ -1831,6 +1831,33 @@ function append_sid($url, $params = false, $is_amp = true, $session_id = false)
 		}
 	}
 
+	$params_is_array = is_array($params);
+
+	// Get anchor
+	$anchor = '';
+	if (strpos($url, '#') !== false)
+	{
+		list($url, $anchor) = explode('#', $url, 2);
+		$anchor = '#' . $anchor;
+	}
+	else if (!$params_is_array && strpos($params, '#') !== false)
+	{
+		list($params, $anchor) = explode('#', $params, 2);
+		$anchor = '#' . $anchor;
+	}
+
+	// Handle really simple cases quickly
+	if ($_SID == '' && $session_id === false && empty($_EXTRA_URL) && !$params_is_array && !$anchor)
+	{
+		if ($params === false)
+		{
+			return $url;
+		}
+
+		$url_delim = (strpos($url, '?') === false) ? '?' : (($is_amp) ? '&amp;' : '&');
+		return $url . ($params !== false ? $url_delim. $params : '');
+	}
+
 	// Assign sid if session id is not specified
 	if ($session_id === false)
 	{
@@ -1843,18 +1870,6 @@ function append_sid($url, $params = false, $is_amp = true, $session_id = false)
 	// Appending custom url parameter?
 	$append_url = (!empty($_EXTRA_URL)) ? implode($amp_delim, $_EXTRA_URL) : '';
 
-	$anchor = '';
-	if (strpos($url, '#') !== false)
-	{
-		list($url, $anchor) = explode('#', $url, 2);
-		$anchor = '#' . $anchor;
-	}
-	else if (!is_array($params) && strpos($params, '#') !== false)
-	{
-		list($params, $anchor) = explode('#', $params, 2);
-		$anchor = '#' . $anchor;
-	}
-
 	// Use the short variant if possible ;)
 	if ($params === false)
 	{