diff --git a/docs/building-deployer.md b/docs/building-deployer.md
index 93abee5a..3c0c5149 100644
--- a/docs/building-deployer.md
+++ b/docs/building-deployer.md
@@ -36,6 +36,10 @@ Decide how to craft your application k8s manifests.
   k8s. The downside is that templating capabilities are very limited.
   Follow instructions [here](building-deployer-envsubst.md).
 
+Note that whichever deployer guide you choose to follow, a `schema.yaml` file is
+required. It declares parameters required for provisioning the application. See
+[here](schema.md) for a reference of this file.
+
 ## Publishing a new version
 
 A new application version is submitted by pushing the corresponding deployer image