Enabling databinding with Kotlin DSL

I have a small problem after migrating an Android Studio project to Kotlin DSL. Databinding dependencies seem to be broken. I expect I’ve done something silly in my build.gradle.kts to cause this, but so far I haven’t been able to work out what that might be.

In my build.gradle.kts I have:

dataBinding.isEnabled = true

Is this the right way to enable databinding, or do I need to do something else?

(NB, also posted to Stack Overflow with a few more details)