diff --git a/docs/usage.md b/docs/usage.md
index 768b1b08..d061afdf 100644
--- a/docs/usage.md
+++ b/docs/usage.md
@@ -74,7 +74,7 @@ The command would create a service `foo` that exposes ports `8080` and `8081`. A
 
 Indexes are incremental and start with `1`.
 
-## Environment Variables
+### Environment Variables
 
 When a service is not part of the same Swarm cluster, a failure of a proxy instance means that the information about those services cannot be obtained through Docker API and *Docker Flow Swarm Listener*. In such a case, data loss can be prevented through the usage of environment variables.