Methods are disclosed of modifying an integrated circuit (IC) design that utilizes multiple patterning technology (MPT). The methods include configuring a first layout of an integrated circuit, having at least one layer with features to be formed utilizing fabrication by at least two masks. The at least one layer includes a plurality of active cells and a plurality of spare cells. A second layout is configured to re-route the spare cells and active cells, wherein the re-routing utilizes at least a portion of the plurality of spare cells. Fewer than all of the at least two masks are replaced to configure the second layout.