diff --git a/README.md b/README.md
index 4a87c96..57c5099 100644
--- a/README.md
+++ b/README.md
@@ -70,12 +70,13 @@ docker build -t felis:custom .
 
 ## 开源协议
 
-本项目代码部分遵循 MIT License 开源协议。
+本项目遵循 [AGPL-3.0-only](LICENSE) 开源协议。
 
 ### 协议注意事项
 
-1. **保留版权声明**：在您分发本项目的副本或基于本项目衍生的软件中，必须包含原作者的版权声明和许可声明。
-2. **免责声明**：本项目按"原样"提供，作者不承担任何因使用本项目而产生的法律责任。
+1. **衍生作品同样是 AGPL**：分发本项目的副本或基于本项目衍生的软件时，必须以 AGPL-3.0 开源，并保留原作者的版权声明和许可声明。
+2. **通过网络提供服务同样要开源**（AGPL 第 13 条）：如果你把修改过的 Felis 架起来给别人用，即使从不分发任何二进制，也必须向这些用户提供你那份修改后的完整源码。这是 AGPL 相对 GPL 的唯一实质区别，而 Felis 正是一个跑在网络上的托管平台，所以这一条基本总会触发。
+3. **免责声明**：本项目按"原样"提供，作者不承担任何因使用本项目而产生的法律责任。
 
 ## 致谢
 
diff --git a/README_EN.md b/README_EN.md
index 65853b7..8758511 100644
--- a/README_EN.md
+++ b/README_EN.md
@@ -53,12 +53,13 @@ docker build -t felis:custom .
 
 ## License
 
-The source code is released under the MIT License.
+The source code is released under [AGPL-3.0-only](LICENSE).
 
 ### License Notes
 
-1. **Attribution**: Any distribution of this project or derivative works must include the original copyright notice and license statement.
-2. **Disclaimer**: This project is provided "as is", without warranty of any kind.
+1. **Derivative works are AGPL too**: Any distribution of this project or of software derived from it must be released under AGPL-3.0 and must include the original copyright notice and license statement.
+2. **Running it as a network service also triggers the source obligation** (AGPL section 13): if you host a modified Felis for other people to use, you must offer those users the complete source of your modified version — even if you never distribute a binary. This is the one substantive difference between AGPL and GPL, and since Felis is a hosting platform reached over a network, it will essentially always apply.
+3. **Disclaimer**: This project is provided "as is", without warranty of any kind.
 
 ## Acknowledgements