Fixes #23959

GitHub-Last-Rev: 08ce026f52f9fd65b49d99745dffed46a3951585
GitHub-Pull-Request: golang/go#24012
Change-Id: I7e71c41330346dbc4dad6ba813cabfa8a54e2f66
Reviewed-on: https://go-review.googlesource.com/95975
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>