diff --git a/README.md b/README.md
index f40fcca..87c2bca 100644
--- a/README.md
+++ b/README.md
@@ -184,7 +184,7 @@ pretty dodgy hack is to run it from the system directly:
 root@foo.com /etc/cron.hourly $ cat foo-com-preview-generate 
 #!/bin/bash
 
-docker exec -u www-data $(docker ps -f name=foo_com__app -q) ./occ preview:pre-generate
+docker exec -u www-data $(docker ps -f name=foo_com_app -q) ./occ preview:pre-generate
 ```
 
 This app will improve performance of image browsing at the cost of storage space.