In wireless sensor networks (WSNs), many problems call for the network nodes to be aware of their positions. This makes localization a key and challenging task in WSNs. The scientific literature on this topic distinguishes two major types of solution approaches: range-based versus range-free methods, depending on whether the sensor nodes make use of the range –signal features– of the messages between nodes to estimate their own location. In this work, we propose a heuristic mechanism to improve an existing range-free localization technique termed mobile anchor positioning (MAP). Our heuristic improves MAP’s ability to decide between any two potential position estimates, by performing a voting process with the beacons received by the sensor nodes. Our simulation analysis confirms that our approach reduces MAP’s localization error.