Methods and systems for restimulating a previously fractured subterranean formation penetrated by a wellbore are described. The methods include plugging existing perforations in an outer casing and existing fractures in the formation with a diverting agent, placing an inner casing in the wellbore while the existing perforations and existing fractures are plugged with the diverting agent, perforating the inner casing and the outer casing to form new perforations, and pumping a fluid through the new perforations to create new fractures in the formation.