diff --git a/lam/lib/account.inc b/lam/lib/account.inc
index ca32393aa..26581533d 100644
--- a/lam/lib/account.inc
+++ b/lam/lib/account.inc
@@ -902,7 +902,7 @@ function searchLDAP($suffix, $filter, $attributes, $limit = -1) {
 /**
  * Returns the LDAP server handle.
  *
- * @return handle LDAP handle
+ * @return Connection LDAP handle
  */
 function getLDAPServerHandle() {
 	if (!empty($_SESSION['ldap'])) {
@@ -910,7 +910,7 @@ function getLDAPServerHandle() {
 		return $_SESSION['ldap']->server();
 	}
 	else {
-		// self service
+		// self-service
 		return $_SESSION['ldapHandle']->getServer();
 	}
 }
diff --git a/lam/lib/baseModule.inc b/lam/lib/baseModule.inc
index 52d5a336a..b6c15fbd9 100644
--- a/lam/lib/baseModule.inc
+++ b/lam/lib/baseModule.inc
@@ -1340,7 +1340,7 @@ abstract class baseModule {
 	 *
 	 * Calling this method requires the existence of an enclosing {@link accountContainer}.
 	 *
-	 * @return htmlElement meta HTML object
+	 * @return htmlElement|htmlElement[] meta HTML object
 	 *
 	 * @see htmlElement
 	 */
diff --git a/lam/lib/modules/sambaGroupMapping.inc b/lam/lib/modules/sambaGroupMapping.inc
index 502b36fbb..93a7c92fe 100644
--- a/lam/lib/modules/sambaGroupMapping.inc
+++ b/lam/lib/modules/sambaGroupMapping.inc
@@ -7,7 +7,7 @@ use LAM\TYPES\TypeManager;
 
   This code is part of LDAP Account Manager (http://www.ldap-account-manager.org/)
   Copyright (C) 2003 - 2006  Tilo Lutz
-                2007 - 2024  Roland Gruber
+                2007 - 2025  Roland Gruber
 
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -194,7 +194,7 @@ class sambaGroupMapping extends baseModule {
 	/**
 	 * Gets the GID number from the Unix group module.
 	 *
-	 * @return String GID number
+	 * @return string|null GID number
 	 */
 	private function getGID() {
 		$modules = ['posixGroup', 'rfc2307bisPosixGroup'];
@@ -212,9 +212,9 @@ class sambaGroupMapping extends baseModule {
 	/**
 	 * Gets the cn from the Unix group module.
 	 *
-	 * @return String cn attribute
+	 * @return string|null cn attribute
 	 */
-	private function getCn() {
+	private function getCn(): ?string {
 		$modules = ['posixGroup', 'groupOfNames', 'groupOfUniqueNames'];
 		for ($i = 0; $i < count($modules); $i++) {
 			if ($this->getAccountContainer()->getAccountModule($modules[$i]) != null) {
@@ -302,7 +302,7 @@ class sambaGroupMapping extends baseModule {
 					$rid = $this->rids[$rid];
 				}
 				// check if RID has to be calculated
-				if (($rid == "") || (!isset($rid))) {
+				if (($rid == "")) {
 					$ridBase = $nameToRIDBase[$rawAccounts[$i][$ids['sambaGroupMapping_domain']]];
 					$partialAccounts[$i]['sambaSID'] = $domSID . "-" . (($partialAccounts[$i]['gidNumber'] * 2) + $ridBase + 1);
 				}
@@ -341,6 +341,7 @@ class sambaGroupMapping extends baseModule {
 			if (isset($this->attributes['sambaSID'][0])) {
 				$domainSID = substr($this->attributes['sambaSID'][0], 0, strrpos($this->attributes['sambaSID'][0], "-"));
 			}
+			$SID = '';
 			for ($i = 0; $i < count($sambaDomains); $i++) {
 				// List with all valid domains
 				$sambaDomainNames[] = $sambaDomains[$i]->name;
@@ -590,13 +591,10 @@ class sambaGroupMapping extends baseModule {
 
 
 	/**
-	 * This function is used to check if this module page can be displayed.
-	 * It returns false if a module depends on data from other modules which was not yet entered.
-	 *
-	 * @return boolean true, if page can be displayed
+	 * {@inheritDoc}
 	 */
 	function module_ready() {
-		return ($this->getGID() != null) && ($this->getGID() != '');
+		return ($this->getGID() !== null) && ($this->getGID() !== '');
 	}
 
 	/**
@@ -653,6 +651,8 @@ class sambaGroupMapping extends baseModule {
 		$this->attributes['sambaGroupType'][0] = $this->sambaGroupTypes[$_POST['sambaGroupType']];
 
 		// Get Domain SID from name
+		$SID = '';
+		$RIDbase = 1000;
 		for ($i = 0; $i < count($sambaDomains); $i++) {
 			if (!isset($_POST['sambaDomainName'])) {
 				break;
@@ -663,7 +663,6 @@ class sambaGroupMapping extends baseModule {
 			}
 		}
 		// Load attributes
-		$this->attributes['displayName'][0] = $_POST['displayName'];
 		$rids = array_keys($this->rids);
 		$wrid = false;
 		for ($i = 0; $i < count($rids); $i++) {
diff --git a/phpstan.neon b/phpstan.neon
index 10f76d1f8..1b74a646c 100644
--- a/phpstan.neon
+++ b/phpstan.neon
@@ -20,6 +20,5 @@ parameters:
 		- '#Function [a-zA-Z0-9\\_-]+ not found.#'
 		- '#Used function [a-zA-Z0-9\\_-]+ not found.#'
 		- '#Variable \$helpArray might not be defined.#'
-		- '#Function [a-zA-Z0-9\(\)\\_-]+ has invalid return type [a-zA-Z0-9\\_-]+.#'
 		- '#Binary operation .* between .* and .* results in an error.#'
 		- '#Offset .SID. on array.*in isset\(\) always exists.*#'