diff --git a/pkg/action/upgrade.go b/pkg/action/upgrade.go
index be1f96273..6c2b2739d 100644
--- a/pkg/action/upgrade.go
+++ b/pkg/action/upgrade.go
@@ -86,7 +86,11 @@ type Upgrade struct {
 	// SubNotes determines whether sub-notes are rendered in the chart.
 	SubNotes bool
 	// Description is the description of this operation
-	Description  string
+	Description string
+	// PostRender is an optional post-renderer
+	//
+	// If this is non-nil, then after templates are rendered, they will be sent to the
+	// post renderer before sending to the Kuberntes API server.
 	PostRenderer postrender.PostRenderer
 	// DisableOpenAPIValidation controls whether OpenAPI validation is enforced.
 	DisableOpenAPIValidation bool