diff --git a/README.md b/README.md
index cbf91c3..5233df9 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,7 @@
-
-
 # functional test:
 ```
+apt -y install coturn
 . /home/docker/turn.$(hostname)/env
 turnutils_uclient -p 5349 -W $TURN_SECRET -v -y turn.$(hostname).
+apt remove --purge coturn
 ```