GNU Autotest is GNU Autoconf's unit testing tool. and is very generic, portable and simple. Autotest is therefore well suited to run tests using other testing tools, such as EUnit (Erlang/OTP's unit testing tool), JUnit, etc. I just added to GNU Autoconf the AT_CHECK_EUNIT macro to run EUnit unit tests in Autotest testsuites. It is the first Autotest macro to integrate such an external testing tool, and will be included in the next version of GNU Autoconf (> 2.64). A complete, working example project using AT_CHECK_EUNIT can be downloaded in autotest-eunit-demo-1.0.tgz. This article shows how to use AT_CHECK_EUNIT by explaining the important parts of this example project.