Energy is one of the crucial performance parameters in wireless sensor networks (WSNs). Enhancement of network lifetime is an important consideration as well. Low energy-aware clustering hierarchy (LEACH) is one of the protocols proposed for WSNs. In this paper, a residual energy-aware clustering transformation protocol for LEACH (REACT-LEACH), enhancing performance of LEACH by introducing a clustering mechanism, is proposed. The proposed cluster head (CH) rotation and cluster reformation processes are more effective in REACT-LEACH, as residual energy is considered to be one of the metrics. Performance of REACT-LEACH is validated based on simulations