diff --git a/geth-mainnet.yml b/geth-mainnet.yml
index 0ea7d484..f4fab80b 100644
--- a/geth-mainnet.yml
+++ b/geth-mainnet.yml
@@ -1,4 +1,7 @@
-geth-mainnet:                         
+version: '3.1'
+
+services:
+  geth-mainnet:                         
     image: ethereum/client-go:stable
     expose: 
       # HTTP server / GraphQL API