diff --git a/lam/lib/security.inc b/lam/lib/security.inc
index 3c6d760be..ba493e04c 100644
--- a/lam/lib/security.inc
+++ b/lam/lib/security.inc
@@ -64,7 +64,7 @@ function startSecureSession($redirectToLogin = true, $initSecureData = false) {
 	if (isset($_SESSION)) {
 		unset($_SESSION);
 	}
-	if (strtolower(session_module_name()) == 'files') {
+	if (isFileBasedSession()) {
 		$sessionDir = dirname(__FILE__) . "/../sess";
 		session_save_path($sessionDir);
 		// enable garbage collection (fix for Debian based systems)
@@ -121,6 +121,15 @@ function startSecureSession($redirectToLogin = true, $initSecureData = false) {
 	return true;
 }
 
+/**
+ * Returns if the session uses files storage.
+ *
+ * @return bool file based session
+ */
+function isFileBasedSession(): bool {
+	return ((session_module_name() !== false) && (strtolower(session_module_name()) === 'files'));
+}
+
 /**
  * Checks if the client's IP address is on the list of allowed IPs.
  * The script is stopped if the host is not valid.
diff --git a/lam/templates/config/confImportExport.php b/lam/templates/config/confImportExport.php
index 1de4b4d5c..ac51aed91 100644
--- a/lam/templates/config/confImportExport.php
+++ b/lam/templates/config/confImportExport.php
@@ -50,7 +50,7 @@ use ZipArchive;
 include_once('../../lib/persistence.inc');
 
 // start session
-if (strtolower(session_module_name()) == 'files') {
+if (isFileBasedSession()) {
 	session_save_path("../../sess");
 }
 lam_start_session();
diff --git a/lam/templates/config/conflogin.php b/lam/templates/config/conflogin.php
index 737233e33..f1aae38a0 100644
--- a/lam/templates/config/conflogin.php
+++ b/lam/templates/config/conflogin.php
@@ -48,7 +48,7 @@ include_once('../../lib/config.inc');
 include_once('../../lib/status.inc');
 
 // start session
-if (strtolower(session_module_name()) == 'files') {
+if (isFileBasedSession()) {
 	session_save_path(dirname(__FILE__) . '/../../sess');
 }
 lam_start_session();
diff --git a/lam/templates/config/confmain.php b/lam/templates/config/confmain.php
index bec1eab86..0eb8a6c34 100644
--- a/lam/templates/config/confmain.php
+++ b/lam/templates/config/confmain.php
@@ -65,7 +65,7 @@ include_once __DIR__ . '/../../lib/2factor.inc';
 include_once __DIR__ . '/../../lib/configPages.inc';
 
 // start session
-if (strtolower(session_module_name()) == 'files') {
+if (isFileBasedSession()) {
 	session_save_path("../../sess");
 }
 lam_start_session();
diff --git a/lam/templates/config/confmodules.php b/lam/templates/config/confmodules.php
index 090cca951..dd11c32c9 100644
--- a/lam/templates/config/confmodules.php
+++ b/lam/templates/config/confmodules.php
@@ -50,7 +50,7 @@ include_once('../../lib/modules.inc');
 include_once '../../lib/configPages.inc';
 
 // start session
-if (strtolower(session_module_name()) == 'files') {
+if (isFileBasedSession()) {
 	session_save_path("../../sess");
 }
 lam_start_session();
diff --git a/lam/templates/config/confsave.php b/lam/templates/config/confsave.php
index 5b8ef87b7..ae059a667 100644
--- a/lam/templates/config/confsave.php
+++ b/lam/templates/config/confsave.php
@@ -42,7 +42,7 @@ include_once(__DIR__ . "/../../lib/config.inc");
 include_once(__DIR__ . "/../../lib/modules.inc");
 
 // start session
-if (strtolower(session_module_name()) == 'files') {
+if (isFileBasedSession()) {
 	session_save_path("../../sess");
 }
 lam_start_session();
diff --git a/lam/templates/config/conftypes.php b/lam/templates/config/conftypes.php
index bd94989d8..cb078210f 100644
--- a/lam/templates/config/conftypes.php
+++ b/lam/templates/config/conftypes.php
@@ -49,7 +49,7 @@ include_once '../../lib/types.inc';
 include_once '../../lib/configPages.inc';
 
 // start session
-if (strtolower(session_module_name()) == 'files') {
+if (isFileBasedSession()) {
 	session_save_path("../../sess");
 }
 lam_start_session();
diff --git a/lam/templates/config/index.php b/lam/templates/config/index.php
index 165444345..0704ab6d3 100644
--- a/lam/templates/config/index.php
+++ b/lam/templates/config/index.php
@@ -36,7 +36,7 @@ use htmlResponsiveRow;
 include_once('../../lib/config.inc');
 
 // start session
-if (strtolower(session_module_name()) == 'files') {
+if (isFileBasedSession()) {
 	session_save_path("../../sess");
 }
 lam_start_session();
diff --git a/lam/templates/config/mainlogin.php b/lam/templates/config/mainlogin.php
index 53db16b34..ad57e3508 100644
--- a/lam/templates/config/mainlogin.php
+++ b/lam/templates/config/mainlogin.php
@@ -38,7 +38,7 @@ if (isLAMProVersion()) {
 }
 
 // start session
-if (strtolower(session_module_name()) == 'files') {
+if (isFileBasedSession()) {
 	session_save_path(dirname(__FILE__) . '/../../sess');
 }
 lam_start_session();
diff --git a/lam/templates/config/mainmanage.php b/lam/templates/config/mainmanage.php
index 6f0316e30..3a8a5b7de 100644
--- a/lam/templates/config/mainmanage.php
+++ b/lam/templates/config/mainmanage.php
@@ -66,7 +66,7 @@ include_once('../../lib/status.inc');
 include_once('../../lib/selfService.inc');
 
 // start session
-if (strtolower(session_module_name()) == 'files') {
+if (isFileBasedSession()) {
 	session_save_path("../../sess");
 }
 lam_start_session();
diff --git a/lam/templates/config/moduleSettings.php b/lam/templates/config/moduleSettings.php
index 555f26654..f2abc9a12 100644
--- a/lam/templates/config/moduleSettings.php
+++ b/lam/templates/config/moduleSettings.php
@@ -44,7 +44,7 @@ include_once('../../lib/types.inc');
 include_once '../../lib/configPages.inc';
 
 // start session
-if (strtolower(session_module_name()) == 'files') {
+if (isFileBasedSession()) {
 	session_save_path("../../sess");
 }
 lam_start_session();
diff --git a/lam/templates/config/profmanage.php b/lam/templates/config/profmanage.php
index 9cd01d018..852d09430 100644
--- a/lam/templates/config/profmanage.php
+++ b/lam/templates/config/profmanage.php
@@ -52,7 +52,7 @@ include_once('../../lib/config.inc');
 include_once('../../lib/status.inc');
 
 // start session
-if (strtolower(session_module_name()) == 'files') {
+if (isFileBasedSession()) {
 	session_save_path("../../sess");
 }
 lam_start_session();
diff --git a/lam/templates/help.php b/lam/templates/help.php
index 69d8c740a..b286b23c0 100644
--- a/lam/templates/help.php
+++ b/lam/templates/help.php
@@ -46,7 +46,7 @@ if (!empty($_GET['selfService']) && ($_GET['selfService'] === '1')) {
 	session_name('SELFSERVICE');
 }
 
-if (strtolower(session_module_name()) == 'files') {
+if (isFileBasedSession()) {
 	session_save_path("../sess");
 }
 lam_start_session();
diff --git a/lam/templates/lib/141_jquery-validationEngine-lang.php b/lam/templates/lib/141_jquery-validationEngine-lang.php
index f90406eaf..bb8662852 100644
--- a/lam/templates/lib/141_jquery-validationEngine-lang.php
+++ b/lam/templates/lib/141_jquery-validationEngine-lang.php
@@ -25,7 +25,7 @@
 include_once(__DIR__ . "/../../lib/config.inc"); // Include config.inc which provides Config class
 
 // set session save path
-if (strtolower(session_module_name()) == 'files') {
+if (isFileBasedSession()) {
 	session_save_path(dirname(__FILE__) . '/../../sess');
 }
 
diff --git a/lam/templates/login.php b/lam/templates/login.php
index d8feade05..842c16fa8 100644
--- a/lam/templates/login.php
+++ b/lam/templates/login.php
@@ -67,7 +67,7 @@ if (isLAMProVersion()) {
 }
 
 // set session save path
-if (strtolower(session_module_name()) == 'files') {
+if (isFileBasedSession()) {
 	session_save_path(dirname(__FILE__) . '/../sess');
 }
 
diff --git a/phpstan.neon b/phpstan.neon
index 6dd2bd670..855b82a80 100644
--- a/phpstan.neon
+++ b/phpstan.neon
@@ -1,5 +1,5 @@
 parameters:
-	level: 6
+	level: 7
 	scanDirectories:
 		- lam/lib
 		- lam/templates