excel - convert cells in to an array of variant

I need to store some cell values into an array of variants. (I'm using this array in a for each loop, so it has to be variant) The following code gives a type mismatch error. Could someone please show me how to do it? Thanks in advance.

Public Sub MainSub()

    Dim ws_names() As Variant
    ws_names = Worksheets("Lookup").Range("K3:K5")
    ShowCertainWorksheets ws_names
End Sub

Public Sub ShowCertainWorksheets(ByVal ws_names As Variant)
    Dim ws_name As Variant
    For Each ws_name In ws_names
        ThisWorkbook.Worksheets(ws_name).Visible = True
    Next ws_name

End Sub

Worksheets("Lookup").Range("K3:K5") contains only worksheet names that exist in the file so there's no problem there...