diff --git a/mediawiki/stack.yml b/mediawiki/stack.yml
index 3406c3b85..a40e67cd6 100644
--- a/mediawiki/stack.yml
+++ b/mediawiki/stack.yml
@@ -2,7 +2,6 @@
 #
 # Access via "http://localhost:8080"
 #   (or "http://$(docker-machine ip):8080" if using docker-machine)
-version: '3'
 services:
   mediawiki:
     image: mediawiki