diff --git a/Core/gb.c b/Core/gb.c
index 5101050..cc13061 100755
--- a/Core/gb.c
+++ b/Core/gb.c
@@ -9,6 +9,7 @@
 #ifndef _WIN32
 #include <sys/select.h>
 #endif
+#include <unistd.h>
 #include "gb.h"
 
 void GB_attributed_logv(GB_gameboy_t *gb, GB_log_attributes attributes, const char *fmt, va_list args)