it looks like immutant wrap-session calls [wrap-undertow-session](https://github.com/immutant/immutant/blob/8407408a99767c35d281d08c9978fcae434e64ce/web/src/immutant/web/internal/undertow.clj#L64) and that doesn't have an option for a custom store

so I think you'd just want to use a the ring wrap-session middleware instead of the immutant one in this case

Thanks Toby Crawley helped me out and I switched to the ring middleware.