diff --git a/classes/context/Context.class.php b/classes/context/Context.class.php
index 8e608862e..083f13920 100644
--- a/classes/context/Context.class.php
+++ b/classes/context/Context.class.php
@@ -321,7 +321,7 @@ class Context
 		$lang_type = preg_replace('/[^a-zA-Z0-9_-]/', '', $lang_type);
 		if ($set_lang_cookie)
 		{
-			setcookie('lang_type', $lang_type, time() + 86400 * 365, \RX_BASEURL, null, !!config('session.use_ssl_cookies'));
+			setcookie('lang_type', $lang_type, time() + 86400 * 365, \RX_BASEURL, '', !!config('session.use_ssl_cookies'));
 		}
 
 		if(!$lang_type || !isset($enabled_langs[$lang_type]))
diff --git a/classes/mobile/Mobile.class.php b/classes/mobile/Mobile.class.php
index c3e857c1e..186f7eccb 100644
--- a/classes/mobile/Mobile.class.php
+++ b/classes/mobile/Mobile.class.php
@@ -46,7 +46,7 @@ class Mobile
 		$m = Context::get('m');
 		$cookie = isset($_COOKIE['rx_uatype']) ? $_COOKIE['rx_uatype'] : null;
 		$uahash = base64_encode_urlsafe(md5($_SERVER['HTTP_USER_AGENT'] ?? '', true));
-		if (strncmp($cookie, $uahash . ':', strlen($uahash) + 1) !== 0)
+		if (strncmp($cookie ?? '', $uahash . ':', strlen($uahash) + 1) !== 0)
 		{
 			$cookie = null;
 		}
@@ -72,7 +72,7 @@ class Mobile
 		$uatype = $uahash . ':' . (self::$_ismobile ? '1' : '0');
 		if ($cookie !== $uatype)
 		{
-			setcookie('rx_uatype', $uatype, 0, \RX_BASEURL, null, !!config('session.use_ssl_cookies'));
+			setcookie('rx_uatype', $uatype, 0, \RX_BASEURL, '', !!config('session.use_ssl_cookies'));
 			$_COOKIE['rx_uatype'] = $uatype;
 		}
 
diff --git a/common/framework/Session.php b/common/framework/Session.php
index ad6392b9e..c90282673 100644
--- a/common/framework/Session.php
+++ b/common/framework/Session.php
@@ -1261,7 +1261,7 @@ class Session
 	 * @param string $domain (optional)
 	 * @return bool
 	 */
-	protected static function _unsetCookie($name, $path = null, $domain = null)
+	protected static function _unsetCookie($name, $path = '', $domain = '')
 	{
 		$result = setcookie($name, 'deleted', time() - (86400 * 366), $path, $domain, false, false);
 		if ($result)
diff --git a/common/framework/UA.php b/common/framework/UA.php
index 9ee264dce..521b707db 100644
--- a/common/framework/UA.php
+++ b/common/framework/UA.php
@@ -468,12 +468,12 @@ class UA
 		if (in_array($color_scheme, ['light', 'dark']))
 		{
 			$_COOKIE['rx_color_scheme'] = $color_scheme;
-			setcookie('rx_color_scheme', $color_scheme, time() + 86400 * 365, \RX_BASEURL, null, !!config('session.use_ssl_cookies'));
+			setcookie('rx_color_scheme', $color_scheme, time() + 86400 * 365, \RX_BASEURL, '', !!config('session.use_ssl_cookies'));
 		}
 		else
 		{
 			unset($_COOKIE['rx_color_scheme']);
-			setcookie('rx_color_scheme', 'deleted', time() - 86400, \RX_BASEURL, null);
+			setcookie('rx_color_scheme', 'deleted', time() - 86400, \RX_BASEURL);
 		}
 	}
 }