diff --git a/src/composer.json b/src/composer.json
index 99f7f278..c16d0531 100644
--- a/src/composer.json
+++ b/src/composer.json
@@ -30,7 +30,7 @@
     "require": {
         "mibew/handlebars.php": "~0.10.5",
         "mibew/handlebars.php-helpers": "1.*",
-        "symfony/http-foundation": "~2.8.52",
+        "symfony/http-foundation": "~3.2",
         "symfony/routing": "2.6.*",
         "symfony/config": "2.6.*",
         "symfony/yaml": "^5.2",
diff --git a/src/mibew/libs/classes/Mibew/Application.php b/src/mibew/libs/classes/Mibew/Application.php
index ed71f0a7..49bb9c30 100644
--- a/src/mibew/libs/classes/Mibew/Application.php
+++ b/src/mibew/libs/classes/Mibew/Application.php
@@ -361,7 +361,9 @@ class Application implements
         $response->headers->setCookie(CookieFactory::fromRequest($request)->createCookie(
             LOCALE_COOKIE_NAME,
             get_current_locale(),
-            time() + 60 * 60 * 24 * 1000
+            time() + 60 * 60 * 24 * 1000,
+            true,
+            false
         ));
 
         $response->prepare($request);
diff --git a/src/mibew/libs/classes/Mibew/Http/CookieFactory.php b/src/mibew/libs/classes/Mibew/Http/CookieFactory.php
index 24080dcd..c3f8729d 100644
--- a/src/mibew/libs/classes/Mibew/Http/CookieFactory.php
+++ b/src/mibew/libs/classes/Mibew/Http/CookieFactory.php
@@ -83,11 +83,14 @@ class CookieFactory
      * @param string $name The name of the cookie.
      * @param string $value The value of the cookie.
      * @param int|string|\DateTime $expire The time the cookie expires.
-     * @param bool $httpOnly Whether the cookie will be made accessible only
+     * @param bool $http_only Whether the cookie will be made accessible only
      *   through the HTTP protocol.
+     * @param bool $same_site Whether the cookie should be used only on the
+     *   original site. Otherwise (but only if it's already marked as secure)
+     *   it will be marked as SameSite=None
      * @return Cookie
      */
-    public function createCookie($name, $value = null, $expire = 0, $http_only = true)
+    public function createCookie($name, $value = null, $expire = 0, $http_only = true, $same_site = true)
     {
         return new Cookie(
             $name,
@@ -96,7 +99,9 @@ class CookieFactory
             $this->getPath(),
             $this->getDomain(),
             $this->isSecure(),
-            $http_only
+            $http_only,
+            true,
+            !$same_site && $this->isSecure() ? 'None' : false
         );
     }
 
diff --git a/src/mibew/libs/classes/Mibew/RequestProcessor/ThreadProcessor.php b/src/mibew/libs/classes/Mibew/RequestProcessor/ThreadProcessor.php
index dee74313..58beed66 100644
--- a/src/mibew/libs/classes/Mibew/RequestProcessor/ThreadProcessor.php
+++ b/src/mibew/libs/classes/Mibew/RequestProcessor/ThreadProcessor.php
@@ -553,7 +553,17 @@ class ThreadProcessor extends ClientSideProcessor implements
         $thread->renameUser($args['name']);
         // Update user name in cookies
         $data = strtr(base64_encode($args['name']), '+/=', '-_,');
-        setcookie(USERNAME_COOKIE_NAME, $data, time() + 60 * 60 * 24 * 365);
+
+        $cookie_properties = array( 'expires' => time() + 60 * 60 * 24 * 365 );
+        if (version_compare(phpversion(), '7.3.0', '<')) {
+            setcookie(USERNAME_COOKIE_NAME, $data, $cookie_properties['expires']);
+        } else {
+            if ($this->currentRequest && $this->currentRequest->isSecure()) {
+                $cookie_properties['samesite'] = 'None';
+                $cookie_properties['secure'] = true;
+            }
+            setcookie(USERNAME_COOKIE_NAME, $data, $cookie_properties);
+        }
     }
 
     /**