diff --git a/README.md b/README.md
index 871940a..78e1191 100644
--- a/README.md
+++ b/README.md
@@ -15,6 +15,14 @@ A simple QR code generator.
 -   Make (optional, but recommended)
 -   Linux (tested environment)
 
+## Configuration
+
+Before installation, rename the example files:
+
+- `./app/.env.example` → `./app/.env`
+- `./app/internal/view/front/.env.example` → `./app/internal/view/front/.env`
+- `./docker-compose.override.yml.example` → `./docker-compose.override.yml`
+
 ## Installation
 
 ``` bash