diff --git a/modules/authtwitter/lib/Auth/Source/Twitter.php b/modules/authtwitter/lib/Auth/Source/Twitter.php
index 19ff725800132cef6758cdaf9366a9b1a96f0f35..6a0a03e99d92d152a968e1897399d338f445a2e4 100644
--- a/modules/authtwitter/lib/Auth/Source/Twitter.php
+++ b/modules/authtwitter/lib/Auth/Source/Twitter.php
@@ -72,6 +72,7 @@ class Twitter extends \SimpleSAML\Auth\Source
      * Log-in using Twitter platform
      *
      * @param array &$state  Information about the current authentication.
+     * @return void
      */
     public function authenticate(&$state)
     {
@@ -103,6 +104,11 @@ class Twitter extends \SimpleSAML\Auth\Source
         $consumer->getAuthorizeRequest($url, $requestToken);
     }
 
+
+    /**
+     * @param array &$state
+     * @return void
+     */
     public function finalStep(&$state)
     {
         $requestToken = $state['authtwitter:authdata:requestToken'];
diff --git a/modules/authtwitter/www/linkback.php b/modules/authtwitter/www/linkback.php
index cbeed68a7be8028ae0e217cadb15d199948b56af..78c0382a42b9ad56acd10d12c6875eba7297993e 100644
--- a/modules/authtwitter/www/linkback.php
+++ b/modules/authtwitter/www/linkback.php
@@ -20,6 +20,7 @@ if (!array_key_exists(\SimpleSAML\Module\authtwitter\Auth\Source\Twitter::AUTHID
 }
 $sourceId = $state[\SimpleSAML\Module\authtwitter\Auth\Source\Twitter::AUTHID];
 
+/** @var \SimpleSAML\Module\authtwitter\Auth\Source\Twitter|null $source */
 $source = \SimpleSAML\Auth\Source::getById($sourceId);
 if ($source === null) {
     throw new \SimpleSAML\Error\BadRequest(