Hello! I have a test.cpp file: #define BOOST_TEST_DYN_LINK #define BOOST_TEST_MODULE Hello // nothing It contains nothing, but the 2 defines. I have a long Makefile of a large project. I copied the Makefile of the large project to the _unittest dir. I modified the paths in the Makefile to the proper paths. The large project has a main.cpp, which has a main() function. If i want to compile with the boost::unit_test, actually the test.cpp, it says: In file included from ../_unittest/src/test.cpp:31: ../_prog/src/main.cpp: In function ‘int main(int, char**)’: ../_prog/src/main.cpp:603 error: redefinition of ‘int main(int, char**)’ /usr/include/boost/test/unit_test.hpp:57: error: ‘int main(int, char**)’ previously defined here make: *** [../_unittest/src/test.o] Error 1 So the problem is, that there are 2 entry points. main.cpp cannot be modified to contain only the functions to be tested, because a large project relies on it. So the ideal solution would be let the original project code untouched, create a test binary that tests the functions from the large project. I'm a beginner the boost::test, can you help me solve this problem? Tamas