Fixes #24647

Change-Id: I79c2b45cf7fc9c0ed0c7a665472556bd248e7584
Reviewed-on: https://go-review.googlesource.com/104235
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan Mills <bcmills@google.com>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>