diff --git a/README.md b/README.md
index f16dfb8..5b400a4 100644
--- a/README.md
+++ b/README.md
@@ -6,6 +6,16 @@ Compatible with: ERS 5928, ERS 5948, ERS 5952, ERS 5952-PWR+, ERS 59100GTS-PWR+
 
 ---
 
+## Requirements
+
+**Management computer OS: Linux** (Ubuntu / Debian recommended — Raspberry Pi OS works perfectly)
+
+The setup script uses `apt`, `systemd`, `picocom`, and Docker. It will not run on Mac or Windows. The management computer does not need a monitor — a headless Raspberry Pi or thin client is ideal. Once running, the web UI is accessible from any browser on any device on your network.
+
+The switch UI itself (the browser interface) works from any OS — phone, tablet, Mac, Windows, Linux.
+
+---
+
 ## Physical Setup — First Time Out of the Box
 
 Everything here happens before you run any software. You need a console cable and a laptop.