Fixes #19555

Change-Id: I7aa0551a90f6bb630c0ba721f3525a8a9cf793fd
Reviewed-on: https://go-review.googlesource.com/38164
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>