diff --git a/src/Symfony/Bundle/FrameworkBundle/Resources/config/session.xml b/src/Symfony/Bundle/FrameworkBundle/Resources/config/session.xml
index 8b68d9e846dd4..c87f688c78668 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Resources/config/session.xml
+++ b/src/Symfony/Bundle/FrameworkBundle/Resources/config/session.xml
@@ -15,6 +15,7 @@
             <argument type="service" id="session.storage" />
             <argument type="service" id="session.attribute_bag" />
             <argument type="service" id="session.flash_bag" />
+            <tag name="kernel.reset" method="save" />
         </service>
 
         <service id="Symfony\Component\HttpFoundation\Session\SessionInterface" alias="session" />
diff --git a/src/Symfony/Bundle/FrameworkBundle/composer.json b/src/Symfony/Bundle/FrameworkBundle/composer.json
index 78d7ae1e564e7..e5449ff32ef7b 100644
--- a/src/Symfony/Bundle/FrameworkBundle/composer.json
+++ b/src/Symfony/Bundle/FrameworkBundle/composer.json
@@ -23,7 +23,7 @@
         "symfony/dependency-injection": "^3.4.24|^4.2.5",
         "symfony/config": "~3.4|~4.0",
         "symfony/event-dispatcher": "~3.4|~4.0",
-        "symfony/http-foundation": "^3.3.11|~4.0",
+        "symfony/http-foundation": "^3.4.24|^4.2.5",
         "symfony/http-kernel": "~3.4|~4.0",
         "symfony/polyfill-mbstring": "~1.0",
         "symfony/filesystem": "~2.8|~3.0|~4.0",
diff --git a/src/Symfony/Component/HttpFoundation/Session/Session.php b/src/Symfony/Component/HttpFoundation/Session/Session.php
index 867ceba97f8db..62ce948b6828b 100644
--- a/src/Symfony/Component/HttpFoundation/Session/Session.php
+++ b/src/Symfony/Component/HttpFoundation/Session/Session.php
@@ -193,7 +193,9 @@ public function migrate($destroy = false, $lifetime = null)
      */
     public function save()
     {
-        $this->storage->save();
+        if ($this->isStarted()) {
+            $this->storage->save();
+        }
     }
 
     /**
diff --git a/src/Symfony/Component/HttpFoundation/Tests/Session/SessionTest.php b/src/Symfony/Component/HttpFoundation/Tests/Session/SessionTest.php
index afa00fc7c3046..e75b3321b035e 100644
--- a/src/Symfony/Component/HttpFoundation/Tests/Session/SessionTest.php
+++ b/src/Symfony/Component/HttpFoundation/Tests/Session/SessionTest.php
@@ -260,4 +260,14 @@ public function testIsEmpty()
         $flash->get('hello');
         $this->assertTrue($this->session->isEmpty());
     }
+
+    public function testSaveIfNotStarted()
+    {
+        $storage = $this->getMockBuilder('Symfony\Component\HttpFoundation\Session\Storage\SessionStorageInterface')->getMock();
+        $session = new Session($storage);
+
+        $storage->expects($this->once())->method('isStarted')->willReturn(false);
+        $storage->expects($this->never())->method('save');
+        $session->save();
+    }
 }