Test jar dependency not available for for main classes in multi module builds

I have a module layout like this:

root -+- first
      +- second

I have the test-jar plugin enabled, thus a *-tests.jar is built for each module. In the second module, I have defined a dependency to first's tests jar:

       <dependency>
          <groupId>me</groupId>
          <artifactId>first</artifactId>
          <classifier>tests</classifier>
          <version>1.0-SNAPSHOT</version>
          <scope>compile</scope>
       </dependency>

And here's the problem: A class in the second main folder imports a class from the first test folder. If I build the second module separately it builds like it should. But if I build both modules from the root module I get a compilation failure:

/.../root/second/src/main/java/me/SecondMain.java:[3,10] cannot find symbol
symbol  : class FirstTest
location: package me

A class in second's test folder also includes me.FirstTest, and it always compiles. The scope somehow seems to be overridden when doing multi module builds.