A flow cache is a fundamental building block for flow-based traffic processing. Its efficiency is critical for the overall performance of a number of networked devices and systems. However, if not properly managed, the flow cache can be easily filled up and rendered ineffective by traffic patterns such as flooding attacks and scanning activities which, unfortunately, commonly occur in the Internet.In this paper, we show that popular cache replacement policies such as LRU cause the flow caches to evict the so called heavy-hitter flows during flooding attacks. To address this shortcoming, we build upon our recent work [1] and construct a replacement policy that is more resilient to floods and yet performs similarly to other policies under common network traffic conditions.