What I have

I have used Kube secrets for private Docker registry authentication in the default namespace. That works as expected. For example:

$ kubectl get secret regsecret
NAME        TYPE                             DATA      AGE
regsecret   kubernetes.io/dockerconfigjson   1         30m

Which is referenced in my deployment.yml as shown in the snippet below:

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: nginx
spec:
  replicas: 1
  template:
    ...
    spec:
      containers:
      - name:  bootstrap-nginx
        image: quay.io/example/nginx:latest
      ...
      imagePullSecrets:
      - name: regsecret

Here's my question

I need to create the regsecret above in a namepsace, for example, myns as shown below:

$ kubectl get secret regsecret --namespace=myns
NAME        TYPE                             DATA      AGE
regsecret   kubernetes.io/dockerconfigjson   1         30m

With this, how do I reference regsecret from myns namespace into my deployment spec? If I use imagePullSecrets as shown above, it fails saying that Kubernetes could not pull the image (the secret regsecret could not be found). Is there a way to reference "fully qualified" secret name in imagePullSecrets?