diff --git a/modules/understanding-agent-install.adoc b/modules/understanding-agent-install.adoc
index afbf4401c8c..07a8b0d41a4 100644
--- a/modules/understanding-agent-install.adoc
+++ b/modules/understanding-agent-install.adoc
@@ -112,6 +112,10 @@ For platform `none`:
 * The `none` option requires the provision of DNS name resolution and load balancing infrastructure in your cluster. See _Requirements for a cluster using the platform "none" option_ in the "Additional resources" section for more information.
 
 * See "Deploying OpenShift 4.x on non-tested platforms using the bare metal install method" before you attempt to install an {product-title} cluster in virtualized or cloud environments.
+
+For platform `vsphere`, or for platform `baremetal` on vSphere:
+
+* You must set the `disk.EnableUUID` parameter to `TRUE` on all {product-title} nodes. If this parameter is not enabled, the Agent-based Installer validation fails.
 ====
 
 [NOTE]