diff --git a/newlib/ChangeLog b/newlib/ChangeLog
index 54fbfa8cd..32d0d2e32 100644
--- a/newlib/ChangeLog
+++ b/newlib/ChangeLog
@@ -1,3 +1,8 @@
+2010-11-16  Andrew Makhorin <mao@gnu.org>
+
+	* libc/machine/i386/setjmp.S (longjmp): Per POSIX, return 1 if second
+	argument is 0.
+
 2010-11-16  Ralf Corsépius  <ralf.corsepius@rtems.org>
 
 	* libc/include/sys/types.h: Add _mode_t for __rtems__.
diff --git a/newlib/libc/machine/i386/setjmp.S b/newlib/libc/machine/i386/setjmp.S
index 7cabba4d0..9ecef385b 100644
--- a/newlib/libc/machine/i386/setjmp.S
+++ b/newlib/libc/machine/i386/setjmp.S
@@ -67,6 +67,10 @@ SYM (longjmp):
 
 	movl	8(ebp),edi	/* get jmp_buf */
 	movl	12(ebp),eax	/* store retval in j->eax */
+	testl	eax,eax
+	jne	0f
+	incl	eax
+0:
 	movl	eax,0(edi)
 
 	movl	24(edi),ebp