With such Gradle config I think the inconsistency ...

# spring

[sdeleuze]

With such Gradle config I think the inconsistency comes from the fact that you define Kotlin version at Kotlin plugin level, not Boot managed dependencies, hence my proposal to define it at buildscript.ext level. Notice that we currently do not manage kotlin-stdlib-jdk7 and kotlin-stdlib-jdk8 versions but that will be the case for RC1.