Hi everyone. I just released 9th milestone of scalaz 7.3 for Scala binary versions 2.10.x, 2.11.x and 2.12.x. "org.scalaz" %% "scalaz-core" % "7.3.0-M9" This is NOT binary compatible with 7.2.x and 7.3.x milestones. There are some changes. please refer to the release notes https://github.com/scalaz/scalaz/wiki/7.3.0-M9 Cheers. Kenji (@xuwei-k)