diff --git a/slides/swarm/firstservice.md b/slides/swarm/firstservice.md
index 4385c3b7..ac1bba18 100644
--- a/slides/swarm/firstservice.md
+++ b/slides/swarm/firstservice.md
@@ -203,7 +203,7 @@ class: extra-details
 
 - And then to 4 copies per node:
   ```bash
-  docker service update pingpong --replicas 15 --detach=true
+  docker service update pingpong --replicas 20 --detach=true
   ```
 
 ]