> Without seeing the actual code that casues this warning? No. We're > clever, but we aren't telepathic. :-) You are right, here is the source (but I think it does not say anything): include/serial.h: 26: 27: class Serial: public ModuleBase 28: { 29: public: 30: and the full message: ./include/serial.h:28: warning: alignment of ‘Serial::_ZTV6Serial’ is greater than maximum object file alignment. Using 1 The commandline: /usr/local/bin/avr-g++ -mmcu=at90usb162 -g -Winline --param max-inline-insns-single=2000 -Wall -Os -I./include -c serial.cpp > The problem is caused by the fact that the compiler (or assembler; > could be either) generates a declaration that ���Serial::_ZTV6Serial��� > must be aligned at a particular boundary, but your linker doesn't > support such alignment. The message is reported by the compiler, the linker does not report any problems. Regards K. Gy.