diff --git a/cmd/cloud-controller-manager/controller-manager.go b/cmd/cloud-controller-manager/controller-manager.go
index 0f815a7d1c8..60bac4ac729 100644
--- a/cmd/cloud-controller-manager/controller-manager.go
+++ b/cmd/cloud-controller-manager/controller-manager.go
@@ -29,6 +29,8 @@ import (
 	"k8s.io/kubernetes/cmd/cloud-controller-manager/app/options"
 	_ "k8s.io/kubernetes/pkg/client/metrics/prometheus" // for client metric registration
 	"k8s.io/kubernetes/pkg/cloudprovider"
+	// NOTE: Importing all in-tree cloud-providers is not required when
+	// implementing an out-of-tree cloud-provider.
 	_ "k8s.io/kubernetes/pkg/cloudprovider/providers"
 	_ "k8s.io/kubernetes/pkg/version/prometheus" // for version metric registration
 	"k8s.io/kubernetes/pkg/version/verflag"