Hi, I've got a small problem with the C extension feature. It happens when your C (or Pyrex) extension is spread across several C sources, and you have a custom .h file to make the glue. Say: setup( ... ext_modules = [ Extension('mycext', [ 'src/custom1.c', 'src/custom2.c', ], include_dirs=['src']), ] Let's say custom1.c and custom2.c both include src/custom.h. The problem is when you only change src/custom.h without changing one of the C files. Setuptools does not know that custom.h is part of the C extension code, thus "setup.py build" doesn't rebuild it. Even trying "setup.py clean build" does not result into an actual rebuild. Also, including "src/custom.h" into the extension file list does not work, setuptools complaining that it doesn't know about ".h" files. Is there a clean way to have setuptools do a rebuild when the .h file is changed? Thanks, Antoine.