Fixes #23675

Change-Id: I78e13d1ca90400e4dd48674b93bb6e2e30718d97
GitHub-Last-Rev: f2b3a59d2bd92f28fc06360e7920c37b9da0af01
GitHub-Pull-Request: golang/go#25287
Reviewed-on: https://go-review.googlesource.com/112037Reviewed-by: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>