Erroneous unit test compilation behavior

[chjdev]

I'm running into erroneous behavior while testing. I organize my projects in src and test folders like:
src/hello.erl
test/hello_tests.erl
(marked as source folder and test folder respectively)

When I run the test suite, the source file hello.erl is copied/compiled to the out/test/... directory only the first time. In sequential runs it only gets updated in out/production/... . However, when I change the test file hello_tests.erl itself, hello.erl is updated in both places.
This means i have to introduce trivial changes in the test file to trigger recompilation.

intellij 14.0.1
intellij-erlang v0.5.9
Mac OSX 10.10.1