@mranger90 said in How to link an .obj-File in the build process of Qt (qmake): Does adding something like this to your profile work ? OBJECTS_DIR += $$PWD OBJECTS += objtest.o Obviously I tried this on Linux, so drop the ".o" and you may need to replace it with ".obj" Hi @mranger90, ni4882.obj is not really a object, but a linker input file. The real functions are in ni4882.dll. So using LIBS is the correct way, the only strange thing is that the linker input file uses the extension .obj. But this can easily be fixed by renaming. Regards.