Fixes #17811

Change-Id: I7bf9cbc5245417047ad28a14d9b9ad6592607d3d
Reviewed-on: https://go-review.googlesource.com/32774Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>