diff --git a/README.md b/README.md
index bbc4e42..d3f9dd8 100644
--- a/README.md
+++ b/README.md
@@ -15,8 +15,6 @@ Note: Experimental.
 See also the included `docker-compose.yml` file in this repository.
 
 ```yml
-version: "3"
-
 services:
   cocoda:
     image: ghcr.io/gbv/cocoda-versions
diff --git a/docker-compose.yml b/docker-compose.yml
index 91dd6bc..78eb82c 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -1,5 +1,3 @@
-version: "3"
-
 # Compose file for local testing
 
 services: