Local monitoring has been demonstrated as a powerful technique for mitigating security attacks in multi-hop ad-hoc networks. In local monitoring, nodes overhear partial neighborhood communication to detect misbehavior such as packet drop or delay. However, local monitoring as presented in the literature is vulnerable to stealthy packet dropping through transmission power control. Stealthy packet dropping disrupts the packet from reaching the destination by malicious behavior at an intermediate node. However, the malicious node gives the impression to its neighbors that it performed the legitimate forwarding action. Moreover, a legitimate node comes under suspicion. We provide a protocol called MPC to remedy the attack. MPC expands the set of possible monitors of a node by redefining the monitor role and functionality. We show through analysis and simulation that the basic local monitoring (BLM) fails to efficiently mitigate stealthy power control attacks while MPC successfully mitigates them.