Fixes #30751

Change-Id: I1f783578df499d52eaec3690303671661c8bf5fb
Reviewed-on: https://go-review.googlesource.com/c/go/+/169725
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>