diff --git a/engine/swarm/swarm-tutorial/index.md b/engine/swarm/swarm-tutorial/index.md
index 656418f88e..e96ec35090 100644
--- a/engine/swarm/swarm-tutorial/index.md
+++ b/engine/swarm/swarm-tutorial/index.md
@@ -114,8 +114,8 @@ The following ports must be available. On some systems, these ports are open by
 * **TCP** and **UDP port 4789** for overlay network traffic
 
 If you are planning on creating an overlay network with encryption (`--opt encrypted`),
-you will also need to ensure protocol 50 (ESP) is open.
+you will also need to ensure port 50 (ESP) is open.
 
 ## What's next?
 
-After you have set up your environment, you are ready to [create a swarm](create-swarm.md).
\ No newline at end of file
+After you have set up your environment, you are ready to [create a swarm](create-swarm.md).