Deploy to Engine Yard failing: 'key not found: :ciphers'

I can't deploy using the ey command:

$ ey deploy -e myapp
Loading application data from Engine Yard Cloud...
key not found: :ciphers

engineyard version 3.2.5
ruby 2.5.3p105 (2018-10-18 revision 65156) [x86_64-darwin18]

I think this has something to do with ssl. Ruby 2.5.3 was installed with rbenv and is using openssl 1.1.1 (I think I remember seeing that) though not sure how to find this after actual install...