Lint: "Newer Library Versions Available" when using variables

I have a project with 3 sub-projects. I want the 3 sub-projects to use the same dependencies versions so I factored all the versions in the root build.gradle:

allprojects {
ext.versions = [
        supportLibVersion: '26.1.0',
        playServicesVersion: '11.2.2',
        retrofitVersion: '2.1.0',
        retrofitConverterGsonVersion: '2.1.0',
        retrofitRxjava2AdapterVersion: '1.0.0',
        rxjava2Version: '2.0.5',
        rxandroidVersion: '2.0.1',
        timberVersion: '4.5.1',
        ...
]
}

Now lint doesn't highlight new libraries available anymore. It somehow still works for the supportLibs but not for the other ones.

Any chance I can have this working again?