Fixes golang/go#30694

Change-Id: I12a0a870e4aee6576e879d88a4868666ef448298
Reviewed-on: https://go-review.googlesource.com/c/go/+/167681
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: JP Sugarbroad <jpsugar@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>