Fixes #21742

Change-Id: Ib56b092c490c27a4ba7ebdb6391f1511794710b8
Reviewed-on: https://go-review.googlesource.com/61034
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>