diff --git a/src/main.cpp b/src/main.cpp
index 0fa6d67..ef601d4 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -195,8 +195,8 @@ static void normal_operation(const String& mac) {
         }
         // No stored image yet: keep current display (e-ink is persistent)
     } else if (code == 404) {
-        // Device not registered — show red border indication
-        epd_fill(COLOR_RED);
+        // Device not registered — show setup QR so user can link this device
+        show_setup_qr(mac);
     } else {
         // Server error / timeout: yellow border indication (server reachable, sync failed)
         epd_fill(COLOR_YELLOW);