diff --git a/README.md b/README.md
index 53dc130..030c96d 100644
--- a/README.md
+++ b/README.md
@@ -2,6 +2,7 @@
 
 To get elasticsearch to run, you'll need to run this on the host:
 sysctl -w vm.max_map_count=262144
+(add to /etc/sysctl.conf to make it persistent)
 
 You can build and start all three containers (nextcloud, db and elasticsearch) with: