In ACISP 2006, Peng et al proposed a novel range test technique, which tests whether the integer encrypted in a ciphertext is in an interval range. Their solution is more eﬃcient than any previous solution to range test. However, their technique only works in the passive adversary model, so cannot be widely applied. In this paper, the range test by Peng et al is optimised to be secure in the active adversary model. Although the new range test protocol is less eﬃcient than the original scheme by Peng et al, it is still an efﬁcient solution and can be employed in a much wider application area.