diff --git a/Auth/Auth.php b/Auth/Auth.php
index 4c0ba9467..6f429b4fc 100644
--- a/Auth/Auth.php
+++ b/Auth/Auth.php
@@ -70,12 +70,12 @@ class Auth
     /**
      * Authenticates user.
      *
-     * @return bool
+     * @return mixed
      *
      * @since  1.0.0
      * @author Dennis Eichhorn <d.eichhorn@oms.com>
      */
-    public function authenticate() : bool
+    public function authenticate()
     {
         $uid = $this->session->get('UID');
 
diff --git a/DataStorage/Database/Query/Grammar/Grammar.php b/DataStorage/Database/Query/Grammar/Grammar.php
index 3ee4a1852..25f18fefe 100644
--- a/DataStorage/Database/Query/Grammar/Grammar.php
+++ b/DataStorage/Database/Query/Grammar/Grammar.php
@@ -283,7 +283,7 @@ class Grammar extends GrammarAbstract
 
             return $this->valueQuotes . $value . $this->valueQuotes;
         } elseif (is_int($value)) {
-            return $value;
+            return (string) $value;
         } elseif (is_array($value)) {
             $values = '';
 
diff --git a/DataStorage/Session/HttpSession.php b/DataStorage/Session/HttpSession.php
index becda2073..4ea6eddd8 100644
--- a/DataStorage/Session/HttpSession.php
+++ b/DataStorage/Session/HttpSession.php
@@ -80,7 +80,7 @@ class HttpSession implements SessionInterface
             session_id($sid);
         }
 
-        session_set_cookie_params($liftetime, '/', null, false, true);
+        session_set_cookie_params($liftetime, '/', '', false, true);
         session_start();
         $this->sessionData = $_SESSION;
         $_SESSION          = null;
diff --git a/System/File/Ftp/File.php b/System/File/Ftp/File.php
index 4e2341ade..76c8281b2 100644
--- a/System/File/Ftp/File.php
+++ b/System/File/Ftp/File.php
@@ -60,7 +60,7 @@ class File extends FileAbstract implements FileInterface
             || (!$exists && ($mode & ContentPutMode::CREATE) === ContentPutMode::CREATE)
         ) {
             if (!Directory::exists(dirname($path))) {
-                Directory::create(dirname($path), '0644', true);
+                Directory::create(dirname($path), 0644, true);
             }
 
             $stream = fopen('data://temp,' . $content, 'r');
@@ -276,7 +276,7 @@ class File extends FileAbstract implements FileInterface
 
         if ($overwrite || !self::exists($to)) {
             if (!Directory::exists(dirname($to))) {
-                Directory::create(dirname($to), '0644', true);
+                Directory::create(dirname($to), 0644, true);
             }
 
             return ftp_rename($con, $from, $to);
diff --git a/System/File/Local/Directory.php b/System/File/Local/Directory.php
index 2ea209d34..d79a1bab4 100644
--- a/System/File/Local/Directory.php
+++ b/System/File/Local/Directory.php
@@ -288,7 +288,7 @@ class Directory extends FileAbstract implements DirectoryInterface
     /**
      * {@inheritdoc}
      */
-    public static function create(string $path, string $permission = '0644', bool $recursive = false) : bool
+    public static function create(string $path, int $permission = 0644, bool $recursive = false) : bool
     {
         if (!file_exists($path)) {
             mkdir($path, $permission, $recursive);
diff --git a/System/File/Local/File.php b/System/File/Local/File.php
index 430562496..fed52659b 100644
--- a/System/File/Local/File.php
+++ b/System/File/Local/File.php
@@ -81,7 +81,7 @@ class File extends FileAbstract implements FileInterface
             || (!$exists && ($mode & ContentPutMode::CREATE) === ContentPutMode::CREATE)
         ) {
             if (!Directory::exists(dirname($path))) {
-                Directory::create(dirname($path), '0644', true);
+                Directory::create(dirname($path), 0644, true);
             }
 
             file_put_contents($path, $content);
@@ -259,7 +259,7 @@ class File extends FileAbstract implements FileInterface
 
         if ($overwrite || !file_exists($to)) {
             if (!Directory::exists(dirname($to))) {
-                Directory::create(dirname($to), '0644', true);
+                Directory::create(dirname($to), 0644, true);
             }
 
             copy($from, $to);
@@ -281,7 +281,7 @@ class File extends FileAbstract implements FileInterface
 
         if ($overwrite || !file_exists($to)) {
             if (!Directory::exists(dirname($to))) {
-                Directory::create(dirname($to), '0644', true);
+                Directory::create(dirname($to), 0644, true);
             }
 
             rename($from, $to);
@@ -347,7 +347,7 @@ class File extends FileAbstract implements FileInterface
     {
         if (!file_exists($path)) {
             if (!Directory::exists(dirname($path))) {
-                Directory::create(dirname($path), '0644', true);
+                Directory::create(dirname($path), 0644, true);
             }
 
             if(!is_writable($path)) {