Fixes #25093

Change-Id: If283275e2b73621ade56d014e60c2d18199b366c
Reviewed-on: https://go-review.googlesource.com/122555
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>