D.C. Code § 26-909
In any contract made in pursuance of the provisions of this chapter it shall be unlawful to incorporate any provision for liquidated or other damages as a penalty for any default or forfeiture thereunder.
Feb. 4, 1913, 37 Stat. 660, ch. 26, § 9
1973 Ed., § 26-609.
1981 Ed., § 26-709.