The agreement between the defendant, a building contractor, and a sub-contractor provided that the latter would not "sublet any portion of the work of his contract or hypothecate, pledge, or assign any payments thereunder except by and in accordance with the consent of [the] contractor." Nevertheless, after substantial performance, the subcontractor made an assignment to plaintiff of a part of his claim. Responding to a letter from the assignee requesting an acknowledgment thereof and giving notice of the assignment, defendant acknowledged receipt of the letter, and informed plaintiff that the amount of the indebtedness had not yet been settled, nor all the work approved. Subsequently, defendant paid the assignor. The assignor became insolvent. Plaintiff sued defendant at law. The court, denying recovery, held that mere notice of a partial assignment was insufficient to bind the debtor, and there having been a prohibition against assignment, which was for the benefit of the obligor, any waiver thereof would have to be clear, distinct, and unequivocal, and was not so in the instant case. Concrete Form Co., Inc. for Use of Blairsville Savings & Trust Co. v. W. T. Grange Construction Co., (Pa. 1935) 181 A. 589.