A new approach to partially programmable combinational circuit design that allows masking single stuck-at faults of wires is considered. It is supposed that only one wire may be fault. The combinational circuit consists of gates, look-up tables (LUTs) and Multiplexers (MUXs). The approach is based on using incompletely specified Boolean functions for finding sub-circuits from gates that may be covered by LUTs. The method of reprogramming rectifying LUTs is suggested and the condition of a choice of replacing sub-circuits for internal nodes is formulated.