Fixes #29193

Change-Id: I03088205e51036abbc861ab5b7d141327b0429ae
Reviewed-on: https://go-review.googlesource.com/c/154383Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>