diff -uNr qemu-2.12.1/os-posix.c qemu-2.12.1.mod/os-posix.c
--- qemu-2.12.1/os-posix.c	2018-08-03 00:48:53.000000000 +0300
+++ qemu-2.12.1.mod/os-posix.c	2018-09-17 16:27:47.014062580 +0300
@@ -36,6 +36,7 @@
 #include "qemu/error-report.h"
 #include "qemu/log.h"
 #include "qemu/cutils.h"
+#include "lockf_implementation.h"
 
 #ifdef CONFIG_LINUX
 #include <sys/prctl.h>