RPL is a routing protocol for low-power and lossy networks. A malicious node can manipulate header options used by RPL to create topological inconsistencies, thereby causing denial of service attacks, reducing channel availability, increased control message overhead, and higher energy consumption at the targeted node and its neighborhood. RPL overcomes these topological inconsistencies via a fixed threshold, upon reaching which all subsequent packets with erroneous header options are ignored. However, this threshold value is arbitrarily chosen and the performance can be improved by taking into account network characteristics. To address this we present a mitigation strategy that allows nodes to dynamically adapt against a topological inconsistency attack based on the current network conditions. Results from our experiments show that our approach outperforms the fixed threshold and mitigates these attacks without significant overhead.