diff --git a/README-zh.md b/README-zh.md
index 0747863..9e30d7d 100644
--- a/README-zh.md
+++ b/README-zh.md
@@ -53,12 +53,12 @@ wget https://git.io/vpnsetup -O vpnsetup.sh && sudo sh vpnsetup.sh
 - 封装所有的 VPN 流量在 UDP 协议，不需要 ESP 协议支持
 - 可直接作为 Amazon EC2 实例创建时的用户数据使用
 - 包含 `sysctl.conf` 优化设置，以达到更佳的传输性能
-- 已测试： Ubuntu 18.04/16.04, Debian 10/9/8 和 CentOS 8/7/6
+- 已测试： Ubuntu 20.04/18.04/16.04, Debian 10/9/8 和 CentOS 8/7/6
 
 ## 系统要求
 
 一个新创建的 <a href="https://aws.amazon.com/ec2/" target="_blank">Amazon EC2</a> 实例，使用这些映像之一：
-- <a href="https://cloud-images.ubuntu.com/locator/" target="_blank">Ubuntu 18.04 (Bionic) or 16.04 (Xenial)</a>
+- <a href="https://cloud-images.ubuntu.com/locator/" target="_blank">Ubuntu 20.04 (Focal), 18.04 (Bionic) or 16.04 (Xenial)</a>
 - <a href="https://wiki.debian.org/Cloud/AmazonEC2Image" target="_blank">Debian 10 (Buster)</a>[\*](#debian-10-note)<a href="https://wiki.debian.org/Cloud/AmazonEC2Image" target="_blank">, 9 (Stretch) or 8 (Jessie)</a>
 - <a href="https://wiki.centos.org/Cloud/AWS" target="_blank">CentOS 8 (x86_64) with Updates</a> [\*\*](#centos-8-note)
 - <a href="https://aws.amazon.com/marketplace/pp/B00O7WM7QW" target="_blank">CentOS 7 (x86_64) with Updates</a>
@@ -161,7 +161,7 @@ sh vpnsetup.sh
 
 在 VPN 已连接时，客户端配置为使用 <a href="https://developers.google.com/speed/public-dns/" target="_blank">Google Public DNS</a>。如果偏好其它的域名解析服务，编辑 `/etc/ppp/options.xl2tpd` 和 `/etc/ipsec.conf` 并替换 `8.8.8.8` 和 `8.8.4.4`，然后重启服务器。高级用户可以在运行 VPN 脚本时定义 `VPN_DNS_SRV1` 和 `VPN_DNS_SRV2`（可选）。
 
-使用内核支持有助于提高 IPsec/L2TP 性能。它在以下系统上可用： Ubuntu 18.04/16.04, Debian 10/9 和 CentOS 8/7/6. Ubuntu 系统需要安装 `linux-modules-extra-$(uname -r)`（或者 `linux-image-extra`），然后运行 `service xl2tpd restart`。
+使用内核支持有助于提高 IPsec/L2TP 性能。它在以下系统上可用： Ubuntu 16.04-20.04, Debian 9-10 和 CentOS 6-8. Ubuntu 系统需要安装 `linux-modules-extra-$(uname -r)`（或者 `linux-image-extra`），然后运行 `service xl2tpd restart`。
 
 如果需要在安装后更改 IPTables 规则，请编辑 `/etc/iptables.rules` 和/或 `/etc/iptables/rules.v4` (Ubuntu/Debian)，或者 `/etc/sysconfig/iptables` (CentOS/RHEL)。然后重启服务器。
 
diff --git a/README.md b/README.md
index 9c7b634..b6477af 100644
--- a/README.md
+++ b/README.md
@@ -53,12 +53,12 @@ For other installation options and how to set up VPN clients, read the sections
 - Encapsulates all VPN traffic in UDP - does not need ESP protocol
 - Can be directly used as "user-data" for a new Amazon EC2 instance
 - Includes `sysctl.conf` optimizations for improved performance
-- Tested with Ubuntu 18.04/16.04, Debian 10/9/8 and CentOS 8/7/6
+- Tested with Ubuntu 20.04/18.04/16.04, Debian 10/9/8 and CentOS 8/7/6
 
 ## Requirements
 
 A newly created <a href="https://aws.amazon.com/ec2/" target="_blank">Amazon EC2</a> instance, from one of these images:
-- <a href="https://cloud-images.ubuntu.com/locator/" target="_blank">Ubuntu 18.04 (Bionic) or 16.04 (Xenial)</a>
+- <a href="https://cloud-images.ubuntu.com/locator/" target="_blank">Ubuntu 20.04 (Focal), 18.04 (Bionic) or 16.04 (Xenial)</a>
 - <a href="https://wiki.debian.org/Cloud/AmazonEC2Image" target="_blank">Debian 10 (Buster)</a>[\*](#debian-10-note)<a href="https://wiki.debian.org/Cloud/AmazonEC2Image" target="_blank">, 9 (Stretch) or 8 (Jessie)</a>
 - <a href="https://wiki.centos.org/Cloud/AWS" target="_blank">CentOS 8 (x86_64) with Updates</a> [\*\*](#centos-8-note)
 - <a href="https://aws.amazon.com/marketplace/pp/B00O7WM7QW" target="_blank">CentOS 7 (x86_64) with Updates</a>
@@ -161,7 +161,7 @@ If you wish to add, edit or remove VPN user accounts, see <a href="docs/manage-u
 
 Clients are set to use <a href="https://developers.google.com/speed/public-dns/" target="_blank">Google Public DNS</a> when the VPN is active. If another DNS provider is preferred, replace `8.8.8.8` and `8.8.4.4` in both `/etc/ppp/options.xl2tpd` and `/etc/ipsec.conf`, then reboot your server. Advanced users can define `VPN_DNS_SRV1` and optionally `VPN_DNS_SRV2` when running the VPN setup script.
 
-Using kernel support could improve IPsec/L2TP performance. It is available on Ubuntu 18.04/16.04, Debian 10/9 and CentOS 8/7/6. Ubuntu users: Install `linux-modules-extra-$(uname -r)` (or `linux-image-extra`), then run `service xl2tpd restart`.
+Using kernel support could improve IPsec/L2TP performance. It is available on Ubuntu 16.04-20.04, Debian 9-10 and CentOS 6-8. Ubuntu users: Install `linux-modules-extra-$(uname -r)` (or `linux-image-extra`), then run `service xl2tpd restart`.
 
 To modify the IPTables rules after install, edit `/etc/iptables.rules` and/or `/etc/iptables/rules.v4` (Ubuntu/Debian), or `/etc/sysconfig/iptables` (CentOS/RHEL). Then reboot your server.