Xmonad is ignoring my keybinding for switching workspaces

Question

I am new to Xmonad and am having trouble changing the binding combination to switch workspaces. I have changed the default modMask to mod4Mask with modMask = mod4Mask in myConfig. I have then configured mod1Mask shown below which I hoped would have the workspace change by pressing mod+[0-9],

    --
    -- mod-[1..9], Switch to workspace N
    -- mod-shift-[1..9], Move client to workspace N
    --
    [((m .|. mod1Mask, k), windows $ f i)
        | (i, k) <- zip (XMonad.workspaces conf) [xK_1 .. xK_9]
        , (f, m) <- [(W.greedyView, 0), (W.shift, shiftMask)]]
    ++

However, after restarting with mod+q (that I see restarts), I still can only switch workspaces with mod+[0-9]

Is there something I'm missing?