Fixes #23720

Change-Id: I28e0c16503bc043f793e0dab19668f7a66313312
Reviewed-on: https://go-review.googlesource.com/118737
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>