765 ILCS 1005/2.1

Whenever a transfer of tangible or intangible personal property shall be made in which the estate or interest created shall be declared to be an estate or interest not in tenancy in common, but in joint tenancy with right of survivorship, notwithstanding the fact that the transferor is or the transferors are also named as a transferee or as transferees, the estate or interest so created shall have all of the effects of a common law joint tenancy estate. This section shall not apply to nor operate to change the effect of any transfer made prior to the effective date of this amendatory Act.