VBA to clear contents of one cell if a condition exists in another cell

Something like this without the action when L20 is False.

Private Sub Worksheet_Change(ByVal Target As Range)
    If Target.Address(0, 0) <> "B11" Then Exit Sub
    Application.EnableEvents = False
    If [L20] Then [L18].ClearContents
    Application.EnableEvents = True
End Sub