Subleading shape functions and the determination of |Vub|

It is argued that the dominant subleading shape-function contributions to the endpoint region of the charged-lepton energy spectrum in B→Xulν decays can be related in a model-independent way to an integral over the B→Xsγ photon spectrum. The square root of the fraction of B→Xulν events with charged-lepton energy above E0=2.2 GeV can be calculated with a residual theoretical uncertainty from subleading shape-function effects that is safely below the 10% level. These effects have therefore a minor impact on the determination of |Vub|.