Warning after update to router 3.5.0

[c-cherdron]

After a router update I get the following warning:

[vue-router] <router-link>'s event prop is deprecated and has been removed in Vue Router 4. Use the v-slot API to remove this warning: https://next.router.vuejs.org/guide/migration/#removal-of-event-and-tag-props-in-router-link.

It appears on the one page which has the vue material stepper in it so I believe that to be the culprint.

[roryschadler]

I'm getting the same warning. It shows up when I use the to attribute on an <md-button> tag.