diff --git a/example1/docker-compose.yml b/example1/docker-compose.yml
index 1cbcc87..c7c5b90 100644
--- a/example1/docker-compose.yml
+++ b/example1/docker-compose.yml
@@ -1,4 +1,4 @@
-version: '3'
+version: '2'
 
 services:
   db: