--- a/util-internal.h 2013-11-01 12:18:57.000000000 -0600 +++ b/util-internal.h 2015-07-20 20:19:43.199560900 -0500 @@ -299,8 +299,13 @@ HANDLE evutil_load_windows_system_librar #if defined(__STDC__) && defined(__STDC_VERSION__) #if (__STDC_VERSION__ >= 199901L) -#define EV_SIZE_FMT "%zu" -#define EV_SSIZE_FMT "%zd" + #if defined(_MSC_VER) || defined(__MINGW32__) || defined(__MINGW64__) + #define EV_SIZE_FMT "%Iu" + #define EV_SSIZE_FMT "%Id" + #else + #define EV_SIZE_FMT "%zu" + #define EV_SSIZE_FMT "%zd" + #endif #define EV_SIZE_ARG(x) (x) #define EV_SSIZE_ARG(x) (x) #endif