diff --git a/docs/design/plugin_system.md b/docs/design/plugin_system.md
index 9c84889f7..3485c40c3 100644
--- a/docs/design/plugin_system.md
+++ b/docs/design/plugin_system.md
@@ -86,7 +86,7 @@ Every plugin has three parts:
         },
         ...
     )
-        ```
+    ```
 
     Please make sure `vllm_add_dummy_platform:register` is a callable function and returns the platform class's fully qualified name. for example: