--- ./modules/highgui/src/window_QT.cpp.orig 2013-10-22 11:01:57.000000000 -0400 +++ ./modules/highgui/src/window_QT.cpp 2013-10-22 11:03:10.000000000 -0400 @@ -46,6 +46,8 @@ #ifdef _WIN32 #include #define usleep Sleep +#else +#include #endif #ifndef M_PI