diff --git a/.env.sample b/.env.sample
index 0368d95887049c67062d1237d387ef8c5a9e1f0d..952bd557879e486bec1fe304101cf0e1b9dc2d2d 100644
--- a/.env.sample
+++ b/.env.sample
@@ -5,6 +5,7 @@ COMPOSE_FILE=docker-compose.yml:ports.yml
 PASS=MON_SUPER_MOT_DE_PASSE
 NAME=kasmVNC
 HOST=kasmVNC.tetras-lab.io
+PORT=6901
 
 # === install module === #
 #
diff --git a/ports.yml b/ports.yml
index 1864e60aa74f84ca40755f452fab818cf7f421d3..68a912b3c266f4429125b0928e807c7b749ba1a7 100644
--- a/ports.yml
+++ b/ports.yml
@@ -1,4 +1,4 @@
 services:
   kasm:
     ports:
-      - 6901:6901
+      - ${PORT}:6901