diff --git a/doc/OCTOPRINT.md b/doc/OCTOPRINT.md
index 5743c36..ddc9db7 100644
--- a/doc/OCTOPRINT.md
+++ b/doc/OCTOPRINT.md
@@ -16,6 +16,8 @@ version: "3"
 services:
   signal-cli-rest-api:
     image: bbernhard/signal-cli-rest-api:latest
+    environment:
+	    - MODE=json-rpc #supported modes: json-rpc, native, normal
     ports:
       - "8080:8080" # map docker port 8080 to host port 8080.
     volumes: