--- a/setserial.c
+++ b/setserial.c
@@ -15,6 +15,9 @@
 #include <termios.h>
 #include <string.h>
 #include <errno.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/ioctl.h>
 
 #ifdef HAVE_ASM_IOCTLS_H
 #include <asm/ioctls.h>