John, After reading your response and thinking about this problem a bit longer, I've come up with two other possible workarounds if the #include_next solution doesn't work. Solution 1. Create a subdirectory called something like "bridges". For each stdc++ header that you need to include, create a bridge header in this subdirectory whose name is _not_ the same as the name of the original header. It might look something like this: File <boost/tr1/iostream>: #include <boost/tr1/bridges/iostream-bridge.hpp> File <boost/tr1/bridges/iostream-bridge.hpp>: #include <iostream> I _think_ that the #include in the bridge header will reliably locate the original stdc++ <iostream> header, since there is no file named "iostream" in the current directory and the bridges directory is not on the search path. Solution 2. Include some stdc++ header that is _not_ being redefined, and then use the value of __GLIBCXX__ to determine the path to the other headers. #if defined(__GLIBCXX__) #if __GLIBCXX__ == 20050421 #include <c++/4.0.0/iostream> #elif __GLIBCXX__ > 20050421 #include <c++/4.2.1/iostream> #else #error Unknown version of the GCC stdc++ library #endif #endif I certainly don't recommend this since it is so fragile, but a solution like this might work if nothing else does. Let me know if you choose to go this route and I'll try to come up with the possible values of __GLIBCXX__ for you and the corresponding paths. I'd also be happy to do a few test builds for you once you think you've come up with a solution, since we do have a vested interest in this working correctly. ;) --Stuart