A normally-off compound semiconductor transistor includes a heterostructure body and a gate stack on the heterostructure body. The heterostructure body includes a source, a drain spaced apart from the source, and a channel for connecting the source and the drain. The channel includes a first two-dimensional charge carrier gas of a first polarity arising in the heterostructure body due to piezoelectric effects. The gate stack controls the channel in a region of the heterostructure body under the gate stack. The gate stack includes at least one III-nitride material which gives rise to a second two-dimensional charge carrier gas of a second polarity opposite the first polarity in the gate stack or in the heterostructure body under the gate stack due to piezoelectric effects. The second two-dimensional charge carrier gas counter-balances polarization charges in the first two-dimensional charge carrier gas so that the channel is disrupted under the gate stack.