A SAPO-34 zeolite membrane was made essentially impermeable to high-pressure hydrogen at room temperature by adsorbing methanol in the SAPO-34 layer. Hydrogen permeance decreased three orders of magnitude when the methanol feed activity was ∼0.1, and it decreased more than six orders of magnitude when the methanol feed activity was higher than 0.85 at 293K. The hydrogen permeance at 293K was below ∼10 −14 mol/m 2 sPa for at least five days for a H 2 feed pressure of 6.6MPa. At higher temperatures, methanol desorbed and the H 2 flux increased. The hydrogen permeance could be controlled by the activity of the methanol on the feed side. These results demonstrate that the SAPO-34 membrane had low fluxes through defects, and H 2 flow through these defects was blocked by capillary condensation of methanol at high methanol activities.