Fixes #16606

Change-Id: I57465061b90e901293cd8b6ef756d6aa84ebd4a3
Reviewed-on: https://go-review.googlesource.com/25495Reviewed-by: Quentin Smith <quentin@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Quentin Smith <quentin@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>