Dear all, I just added a bunch of AC_DEFINE invocations to my configure.ac, with two arguments for each of them: a symbol name and a value. All of them are expanded correctly and the expected header file is generated. As the next step, I wanted to add a description as the third argument, hoping to find this description in the generated header file as documented, but that does not work. I did cleanupu the project to make sure the ancient generated header is deleted, then I did run autoconf and configure again, but the produced header is exactly as if I didn't add a third argument to my macro. The macro call looks like this: AC_DEFINE([PKG_VERSION_MAJOR], [PKG__VERSION_MAJOR], [The major number of the current PKG version]) Can anybody see what I am doing wrong, please? Thanks! Sébastien.