can't run tests for code using CPS?

I've written code using CPS and compiled it. Compilation passed fine (should I have used some kind of switch?)

I've written a Spec for the code, which I run using the Junit runner (JUnit4(MySpec)).

It fails with:

org.specs.runner.SpecError: java.lang.NoSuchMethodError: scala.util.continuations.package$.shift(Lscala/Function1;)Ljava/lang/Object;