diff --git a/CHANGELOG.md b/CHANGELOG.md
index b55f80c01..b8880db35 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,9 @@
     * Added new `Grav\Framework\File\Formatter` classes for encoding/decoding YAML, Markdown, JSON, INI and PHP serialized strings
     * Added `Grav\Common\Media` interfaces and trait; use those in `Page` and `Media` classes 
     * Added `Grav\Common\Page` interface to allow custom page types in the future
+    * Added `Grav\Framework\Session` class to replace `RocketTheme\Toolbox\Session\Session`
+1. [](#improved)
+    * Improved session handling, allow all session configuration options in `system.session.options`
 1. [](#bugfix)
     * Fixed bug in `ContentBlock` serialization
     * Fixed `Route::withQueryParam()` to accept array values
diff --git a/system/src/Grav/Framework/Session/Session.php b/system/src/Grav/Framework/Session/Session.php
index ac6b96b61..db359342f 100644
--- a/system/src/Grav/Framework/Session/Session.php
+++ b/system/src/Grav/Framework/Session/Session.php
@@ -32,7 +32,7 @@ class Session implements \IteratorAggregate
      */
     public static function instance()
     {
-        if (!isset(self::$instance)) {
+        if (null === self::$instance) {
             throw new \RuntimeException("Session hasn't been initialized.", 500);
         }
 
@@ -46,14 +46,14 @@ public static function instance()
     public function __construct(array $options = [])
     {
         // Session is a singleton.
-        if (php_sapi_name() === 'cli') {
+        if (\PHP_SAPI === 'cli') {
             self::$instance = $this;
 
             return;
         }
 
-        if (isset(self::$instance)) {
-            throw new \RuntimeException("Session has already been initialized.", 500);
+        if (null !== self::$instance) {
+            throw new \RuntimeException('Session has already been initialized.', 500);
         }
 
         // Destroy any existing sessions started with session.auto_start
@@ -147,6 +147,7 @@ public function setOptions(array $options)
     /**
      * Starts the session storage
      *
+     * @param bool $readonly
      * @return $this
      * @throws \RuntimeException
      */
@@ -357,7 +358,7 @@ public function started()
      */
     protected function isSessionStarted()
     {
-        return php_sapi_name() !== 'cli' ? \PHP_SESSION_ACTIVE === session_status() : false;
+        return \PHP_SAPI !== 'cli' ? \PHP_SESSION_ACTIVE === session_status() : false;
     }
 
     /**