Defendants-appellants (hereinafter called defendant even though there were other defendants in the trial court) appeal as of right from the November 17, 1978, judgment of the trial court awarding plaintiffs $203,446.59 plus seven per cent interest, pursuant to a lease agreement.
Plaintiffs leased approximately ten acres of land in Ann Arbor, Michigan, for 50 years at $36,000 per year, to defendant Robert Meyer Company, a partnership, which intended to erect a shopping center on the land. Since part of the land was zoned commercial and part was zoned multiple-dwelling, the lease was delivered into escrow on three conditions. First, the lease was to become legally effective upon the subject premise being rezoned in its entirety. Second, if the land was not rezoned by January 3, 1972, then, at the option of the tenant, the lease could be rendered null and void on written notice by the tenant. Third, waiver of the requirement of rezoning would be implied by the tenant’s election not to serve the written notice.
The partnership never gave written notice of termination to plaintiffs. In fact, rather than terminate the lease because of rezoning problems, the partnership assigned its rights and obligations under the lease to Packard Platt Plaza, Inc., a corporation formed for the express purpose of limiting the personal liability of the Robert Meyer Company partners. Packard Platt Plaza, Inc., was incorporated with approximately $1,000 capital. The only assets of the corporation were the lease and additional funds infused to pay corporate *323expenses. Plaintiffs gave written consent to the assignment based upon the understanding that the individual partners of Robert Meyer Company would remain liable under the lease.
The Robert Meyer Company was dissolved in February of 1972, and a partnership was formed to perform work (unrelated to the instant transaction) which had been done prior to that time by the Robert Meyer Company. This partnership was called the Meyer C. Weiner Co.
The lease was delivered out of escrow on March 14, 1972, and the parties orally modified the lease in April of 1972. The modification cut the rent from $36,000 to $18,000 per annum; the lessees agreed to pay the real estate commission; the portion of the property zoned multiple was deleted and plaintiffs agreed to pay one quarter of the taxes on the whole parcel. Payments under the lease were still to begin on May 1, 1972.
. The City of Ann Arbor refused to issue a building permit for the smaller development and the defendant corporation lost its mandamus action when the Michigan Supreme Court refused to hear the case in April of 1976. Plaintiffs instituted this action on April 24, 1975, seeking the unpaid rent on the orally modified lease.
Defendants Meyer C. Weiner and Benjamin H. Rabin first contend that they were released from personal liability by the assignment of the lease to the corporation. We do not agree.
Individuals cannot avoid their responsibility by assigning a lease to a corporation formed solely to avoid liability. The notion of a separate corporate identity distinct from those persons composing the corporation is merely a legal fiction. Montgomery v Central National Bank & Trust Co of Battle Creek, 267 Mich 142, 147-148; 255 NW 274 (1934). *324A corporate veil will be pierced where there is fraud, sham or other improper use of the corporate form. Williams v American Title Ins Co, 83 Mich App 686, 697; 269 NW2d 481 (1978).
In the instant case, defendants Meyer C. Weiner and Benjamin H. Rabin intentionally assigned the lease to an under-capitalized dummy corporation for the purpose of avoiding personal liability under the lease. The trial court did not err when it pierced the corporate veil and held defendants Meyer C. Weiner and Benjamin H. Rabin personally liable on the lease. See Cinderella Theatre Co, Inc v United Detroit Theatres Corp, 367 Mich 424; 116 NW2d 825 (1962).
The individuals next claim that they are not liable under the following assignment provision contained in the lease:
"In the event this Lease shall be assigned to a partnership, tenancy-in-common, joint tenancy, syndicate, joint venture or similar entity or to more than one person, corporation or other entity, all such persons, corporations and entities and all members of such entities shall assume the obligations of this Lease jointly and severally. Nothing contained herein shall preclude the right of a stockholder or owner of interest at the time of the signing of this Lease to transfer all or part of his or their interest by gift or otherwise, to or for the benefit of his wife, children or heirs.”
Under this provision, defendant Joshua T. Weiner was held personally liable as a stockholder of the corporation. The trial court ruled that the understanding of the parties to the lease was the relevant consideration. It concluded that the parties intended to include corporate stockholders within those persons to be personally liable under the lease. The finding of the trial court is not clearly erroneous. GCR 1963, 517.1.
*325Defendants also contend that plaintiffs failed to mitigate their damages as required by Michigan law. However, defendants did not raise this issue before appealing to this Court. This Court has recognized that a landlord has a duty to mitigate damages when a lessee breaches a lease. Tel-Ex Plaza, Inc v Hardees Restaurants, Inc, 76 Mich App 131; 255 NW2d 794 (1977), Froling v Bischoff, 73 Mich App 496; 252 NW2d 832 (1977). Under well settled Michigan authority cited in Froling, supra, the burden is upon the lessee to show, in mitigation of the damages claimed, that the lessor has not used every reasonable effort within his power to so minimize his damages. In addition to waiving this issue by not presenting it to the trial court, defendants failed to meet this burden.
Defendants’ other allegations of error are without merit.
Affirmed.
E. A. Quinnell, J., concurred.