cal -h doesn't disable highlighting

% lsb_release -rd
Description: Ubuntu 17.10
Release: 17.10

% apt-cache policy bsdmainutils
bsdmainutils:
  Installed: 9.0.12+nmu1ubuntu1
  Candidate: 9.0.12+nmu1ubuntu1

The man page for `cal` says the following:

The options are as follows:

      -h Turns off highlighting of today.

Expected output

% cal -h
   December 2017
Su Mo Tu We Th Fr Sa
                1 2
 3 4 5 6 7 8 9
10 11 12 13 14 15 16
17 18 19 20 21 22 23
24 25 26 27 28 29 30
31

Actual output

% cal -h
Usage: cal [general options] [-jy] [[month] year]
       cal [general options] [-j] [-m month] [year]
       ncal -C [general options] [-jy] [[month] year]
       ncal -C [general options] [-j] [-m month] [year]
       ncal [general options] [-bhJjpwySM] [-H yyyy-mm-dd] [-s country_code] [[month] year]
       ncal [general options] [-bhJeoSM] [year]
General options: [-31] [-A months] [-B months] [-d yyyy-mm]

ProblemType: Bug
DistroRelease: Ubuntu 17.10
Package: bsdmainutils 9.0.12+nmu1ubuntu1
ProcVersionSignature: Ubuntu 4.13.0-17.20-generic 4.13.8
Uname: Linux 4.13.0-17-generic x86_64
NonfreeKernelModules: nvidia_uvm nvidia_drm nvidia_modeset nvidia
ApportVersion: 2.20.7-0ubuntu3.5
Architecture: amd64
CurrentDesktop: LXDE
Date: Tue Dec 5 18:13:32 2017
InstallationDate: Installed on 2017-12-04 (1 days ago)
InstallationMedia: Lubuntu 17.10 "Artful Aardvark" - Release amd64 (20171017.1)
SourcePackage: bsdmainutils
UpgradeStatus: No upgrade log present (probably fresh install)