diff -uNr qemu-4.0.0/tcg/i386/tcg-target.inc.c qemu-4.0.0.mod/tcg/i386/tcg-target.inc.c
--- qemu-4.0.0/tcg/i386/tcg-target.inc.c	2019-04-23 21:14:46.000000000 +0300
+++ qemu-4.0.0.mod/tcg/i386/tcg-target.inc.c	2019-04-27 03:36:23.678807870 +0300
@@ -1888,7 +1888,12 @@
 # if defined(__x86_64__) && defined(__linux__)
 #  include <asm/prctl.h>
 #  include <sys/prctl.h>
-int arch_prctl(int code, unsigned long addr);
+#  include <linux/unistd.h>
+static int arch_prctl(int code, unsigned long addr)
+{
+    return syscall(__NR_arch_prctl, code, addr);
+}
+
 static inline int setup_guest_base_seg(void)
 {
     if (arch_prctl(ARCH_SET_GS, guest_base) == 0) {