Fixes #14698

Change-Id: I82fa781bf136c30e900d8e910ff576ba8b218acb
Reviewed-on: https://go-review.googlesource.com/23005
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>