Just to be safe, I would add a pop-door. It would be an extra layer of security. I like a regular wood door I have to open and close. It forces me to physically check the safety of the coop and enclosure every night, and make sure everyone is alright. Forces me up the the mornings, too - to see how they fared the night and check for any overnight breaches in the fence (I have occasionally found some). You can get an automatic door and opener if a manual door doesn't fit your schedule and lifestyle.
I imagine it this way: Without a pop-door, the chickens might well be relatively safe, but predators will still lurk around trying to find a way in. They can SEE the birds, the birds can see and hear the monster and they'll PANIC, and the monster will HEAR and SMELL the birds panicking .... he's just gotta find a way to get at 'em, you know? But with a pop-door in place, the birds are removed from sight. Neither the monster nor the birds will see each other, the birds likely will remain calm and quiet, and the monster will be discouraged from trying further and wander on down the road.
