diff --git a/modules/customize-certificates-api-add-named.adoc b/modules/customize-certificates-api-add-named.adoc
index 3984d11e72..53e5e4f6dc 100644
--- a/modules/customize-certificates-api-add-named.adoc
+++ b/modules/customize-certificates-api-add-named.adoc
@@ -69,7 +69,7 @@ $ oc patch apiserver cluster \
      [{"names": ["<FQDN>"], //<1>
      "servingCertificate": {"name": "<secret>"}}]}}}' <2>
 ----
-<1> Replace `<FQDN>` with the FQDN that the API server should provide the certificate for.
+<1> Replace `<FQDN>` with the FQDN that the API server should provide the certificate for. Do not include the port number.
 <2> Replace `<secret>` with the name used for the secret in the previous step.
 
 . Examine the `apiserver/cluster` object and confirm the secret is now