diff --git a/mastodon/docker-compose.yml b/mastodon/docker-compose.yml
index 4c04160..f05bfa0 100644
--- a/mastodon/docker-compose.yml
+++ b/mastodon/docker-compose.yml
@@ -1,4 +1,4 @@
-version: '3.7'
+version: '3'
 services:
   db:
     restart: always