The data collected at centre-of-mass energies of 188.6 GeV by ALEPH at LEP, corresponding to an integrated luminosity of 176.2 pb −1 , are analysed in a search for pair-produced charged Higgs bosons H ± . Three analyses are employed to select the τ+νττ− ν ̄τ, c s ̄τ− ν ̄τ and c s ̄s c ̄ final states. No evidence for a signal is found. Upper limits are set on the production cross section as a function of the branching fraction B(H+→τ+ντ) and of the mass mH ± , assuming that the sum of the branching ratios is equal to one. In the framework of a two-Higgs-doublet model, charged Higgs bosons with masses below 65.4 GeV/c 2 are excluded at 95% confidence level independently of the decay mode.