Fixes #14001

Change-Id: I6f9bc3028345081758d8f537c3aaddb2e254e69e
Reviewed-on: https://go-review.googlesource.com/18708Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>