Turn off ringer on Apple Watch for phones calls

I am trying to turn off the ringer for phone calls on the apple watch but I would still like it to "ding" for text messages. I know I can mute all sounds but like I said, I still want it to ding for text messages. Is there a way to just turn off the ringer for phone calls? In the watch app on my iphone I tired Notifications>Phone>Custom and turned the sound toggle off but it is still ringing. Any suggestions?