Recently, IEEE 802.11-based wireless networks have been widely adopted as the main access technology. This type of wireless network is know for its low cost, easy deployment and easy configuration. However, the radio range of access points in an IEEE 802.11-based wireless network is limited, thereby mobile nodes have to switch their access points frequently in order to maintain connections in a mobile environment. The question of how to minimize the handoff latency is still a research challenge in IEEE 802.11 wireless networks. In this paper, a self-configured MAC layer handoff scheme is proposed to shorten the handoff latency by adjusting the MinChannelTime and MaxChannelTime dynamically. Simulation results demonstrate that this scheme can significantly reduce the handoff latency and achieve successful handoff at a reasonable probability.