diff --git a/docs/api-types/issuer/README.md b/docs/api-types/issuer/README.md
index 6a0c52ee1..a72cc9fd0 100644
--- a/docs/api-types/issuer/README.md
+++ b/docs/api-types/issuer/README.md
@@ -6,6 +6,7 @@ certificates, including any configuration required for that source.
 An example of an Issuer is ACME. A simple ACME issuer could be defined as:
 
 ```yaml
+apiVersion: certmanager.k8s.io/v1alpha1
 kind: Issuer
 metadata:
   name: letsencrypt-prod