Stress distributions at interfaces of adhesive lap joints have been widely studied to optimize overall structural strength. However, these studies focussed mainly on the mechanics of adhesive layers. In this paper, a novel concept for a double lap adhesive joint is proposed by introducing a slot in its inner adherend. Numerical simulations employing a finite-element method are used to validate the proposed concept. The results show that the introduction of the slots can smooth the stress distributions along the edges of the interfaces between adhesive and adherend and reduce stress concentration near the cut-off ends of the joint. The results also show that the height of the slots has significant effects on alternating the interfacial stresses. Thus, the proposed concept provides a promising way to optimize double lap adhesive joints for enhanced strength with reduced weight.