Fixes #29541

Change-Id: I006915b020b6e710298c32c05e3de77a7f9b54f3
GitHub-Last-Rev: c7a90a4bbe17fd1904c0942e8b343264fb85cba1
GitHub-Pull-Request: golang/go#29542
Reviewed-on: https://go-review.googlesource.com/c/156277
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>