Fixes #14793

Change-Id: I408056d096cd6a999fa5e349704b5ea8e26d2e4e
Reviewed-on: https://go-review.googlesource.com/23201Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>