--- a/main.c
+++ b/main.c
@@ -18,6 +18,7 @@
#include <unistd.h>
#if defined(__linux__) || defined(__CYGWIN__)
#include <pty.h>
+#include <utmp.h>
#elif defined(__OpenBSD__) || defined(__NetBSD__) || defined(__APPLE__)
#include <util.h>
#else