Open vpn / dns problem


I have the last build and I have express vpn, when I used dd wrt and tomato it was ok but with my new open wrt firmware, I'm connected but the dns are not the expressvpn ones. I get google dns.

I don't know how to do. Cause yes I'm connected but if I want to use netflix I need to use the vpn provider's private dns.

take a look of pics, one with open wrt setup and one with dd wrt setup..


Any help would be appreciated.