it's that problem where the for loop variable doesn't go out of scope... ode/src/geom.cpp(389) : error C2086: 'i' : redefinition ode/src/geom.cpp(398) : error C2086: 'i' : redefinition make: *** [ode/src/geom.obj] Error 2 Also, what about renaming ode/src/objects.h to ode/src/objects_internal.h so it doesn't conflict with include/ode/objects.h?