[UbuntuGnome] Disable horizontal scrolling (16.04)

Hello, all. Just installed Ubuntu Gnome on a Dell Inspiron 11 3162. Everything works remarkably well, but there's one thing that's driving me crazy: I'm can't disable horizontal scrolling on the trackpad in either the Gnome 3 settings or in dconf manager. The option does not exist, although an Inteet search seems to indicate that it should (or at least that it existed in previous versions of Gnome 3).

I have tried a synaptics.conf file and it appears Gnome settings supersede it. Any help would be greatly appreciated, the track pad is already fiddly and adding horizontal scrolling to the mix makes it very frustrating to use.