diff --git a/simplesamlphp-module-privacyidea/lib/Auth/Source/PrivacyideaAuthSource.php b/simplesamlphp-module-privacyidea/lib/Auth/Source/PrivacyideaAuthSource.php
index 3ee9cb1..305a04c 100644
--- a/simplesamlphp-module-privacyidea/lib/Auth/Source/PrivacyideaAuthSource.php
+++ b/simplesamlphp-module-privacyidea/lib/Auth/Source/PrivacyideaAuthSource.php
@@ -148,7 +148,7 @@ public function authenticate(&$state)
      * @param string $username The username the user wrote.
      * @param string $password The password the user wrote.
      */
-    protected function login(string $username, string $password)
+    protected function login($username, $password)
     {
         // Stub.
         SimpleSAML_Logger::debug("privacyIDEA AuthSource login stub");
diff --git a/simplesamlphp-module-privacyidea/lib/Auth/Utils.php b/simplesamlphp-module-privacyidea/lib/Auth/Utils.php
index 2655266..60c6041 100644
--- a/simplesamlphp-module-privacyidea/lib/Auth/Utils.php
+++ b/simplesamlphp-module-privacyidea/lib/Auth/Utils.php
@@ -13,7 +13,7 @@ class sspmod_privacyidea_Auth_Utils
      * @return PIResponse|null An array containing attributes and detail, or NULL.
      * @throws Exception
      */
-    public static function authenticatePI(array &$state, array $formParams)
+    public static function authenticatePI(array &$state, array $formParams): ?PIResponse
     {
         assert('array' === gettype($state));
         assert('array' === gettype($formParams));
@@ -229,7 +229,7 @@ public static function handleLogout()
      * @param array $config
      * @return PrivacyIDEA|null privacyIDEA object or null on error
      */
-    public static function createPrivacyIDEAInstance(array $config)
+    public static function createPrivacyIDEAInstance(array $config): ?PrivacyIDEA
     {
         if (!empty($config['privacyideaServerURL']))
         {
@@ -414,7 +414,7 @@ public static function processPIResponse(string $stateId, PIResponse $response):
      * Determine the clients IP-Address.
      * @return string|null The IP-Address of the client.
      */
-    public static function getClientIP()
+    public static function getClientIP(): ?string
     {
         $result = @$_SERVER['HTTP_X_FORWARDED_FOR'] ?: @$_SERVER['REMOTE_ADDR'] ?: @$_SERVER['HTTP_CLIENT_IP'];
         SimpleSAML_Logger::debug('privacyIDEA: client ip: ' . $result);
@@ -447,4 +447,4 @@ public static function checkUidKey(array $config, array $state): array
         }
         return $config;
     }
-}
+}
\ No newline at end of file