diff --git a/libc/arch-x86/string/rindex.S b/libc/arch-x86/string/rindex.S
new file mode 100644
index 0000000..0260d38
--- /dev/null
+++ b/libc/arch-x86/string/rindex.S
@@ -0,0 +1,29 @@
+/*	$OpenBSD: rindex.S,v 1.3 2005/08/07 11:30:38 espie Exp $ */
+/*
+ * Written by J.T. Conklin <jtc@netbsd.org>.
+ * Public domain.
+ */
+
+#include <machine/asm.h>
+
+#ifdef STRRCHR
+ENTRY(strrchr)
+#else
+ENTRY(rindex)
+#endif
+	pushl	%ebx
+	movl	8(%esp),%edx
+	movb	12(%esp),%cl
+	xorl	%eax,%eax		/* init pointer to null */
+	.align 2,0x90
+L1:
+	movb	(%edx),%bl
+	cmpb	%bl,%cl
+	jne	L2
+	movl	%edx,%eax
+L2:
+	incl	%edx
+	testb	%bl,%bl			/* null terminator??? */
+	jnz	L1
+	popl	%ebx
+	ret