diff --git a/libc/arch-x86/include/machine/setjmp.h b/libc/arch-x86/include/machine/setjmp.h
new file mode 100644
index 0000000..ded095d
--- /dev/null
+++ b/libc/arch-x86/include/machine/setjmp.h
@@ -0,0 +1,8 @@
+/*	$OpenBSD: setjmp.h,v 1.2 2000/08/05 22:07:32 niklas Exp $	*/
+/*	$NetBSD: setjmp.h,v 1.1 1994/12/20 10:36:43 cgd Exp $	*/
+
+/*
+ * machine/setjmp.h: machine dependent setjmp-related information.
+ */
+
+#define	_JBLEN	10		/* size, in longs, of a jmp_buf */