Fixes #22250

Change-Id: I0e39d10ff6f0785cd22b0105de2d839e569db4b7
Reviewed-on: https://go-review.googlesource.com/70810
Run-TryBot: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>