In plan reuse, refitting is the process of modifying an existing plan to make it applicable to a new problem situation. An efficient refitting strategy needs to be conservative, i.e., it should minimally modify the existing plan to fit it to the new problem situation. In this paper we present techniques for conservative refitting control by utilizing the annotated dependency structures of an existing plan. The dependency structures arc used to select the refitting choices that minimize disturbance to the applicable parts of the existing plan. This localizes the refitting process and minimizes the cost of refitting. We describe how these techniques are incorporated into PRIAR, a framework for flexible plan reuse.