A heel unit for a touring binding, wherein the heel unit is adjustable between a downhill position, in which it retains a heel portion of a touring boot, and a touring position, in which it releases the heel portion, such that the touring boot can lift up from heel unit, and wherein the heel unit comprises: a base with a fastening arrangement for fastening to a ski, wherein the base has a pivot bearing that defines an axis of rotation extending orthogonally to a ski plane, and a binding body that has coupling means for coupling with the heel portion of the touring boot and is mounted on the pivot bearing rotatably about the axis of rotation in such a way that, in the downhill position, the coupling means point in a forwards direction in order to engage the heel portion of the touring boot and, in the touring position, the coupling means point in a direction other than the forwards direction, and wherein, in the touring position of the heel unit, in the event of a load with a force component acting perpendicularly to the ski plane being applied by the heel portion of the touring boot to the binding body, the binding body and the base are set up to engage with one another so as to prevent rotation of the binding body about the axis of rotation of the pivot bearing of the base, characterised in that the binding body comprises a flap fastened in particular swivellably to the binding body, which flap is adjustable between an engaged position, in which the flap is engaged with the base, and a decoupled position, in which the flap is not engaged with the base. wherein the heel unit is adjustable between a downhill position, in which it retains a heel portion of a touring boot, and a touring position, in which it releases the heel portion, such that the touring boot can lift up from heel unit, and wherein the heel unit comprises: a base with a fastening arrangement for fastening to a ski, wherein the base has a pivot bearing that defines an axis of rotation extending orthogonally to a ski plane, and a binding body that has coupling means for coupling with the heel portion of the touring boot and is mounted on the pivot bearing rotatably about the axis of rotation in such a way that, in the downhill position, the coupling means point in a forwards direction in order to engage the heel portion of the touring boot and, in the touring position, the coupling means point in a direction other than the forwards direction, and wherein, in the touring position of the heel unit, in the event of a load with a force component acting perpendicularly to the ski plane being applied by the heel portion of the touring boot to the binding body, the binding body and the base are set up to engage with one another so as to prevent rotation of the binding body about the axis of rotation of the pivot bearing of the base, characterised in that the binding body comprises a flap fastened in particular swivellably to the binding body, which flap is adjustable between an engaged position, in which the flap is engaged with the base, and a decoupled position, in which the flap is not engaged with the base. a base with a fastening arrangement for fastening to a ski, wherein the base has a pivot bearing that defines an axis of rotation extending orthogonally to a ski plane, and a binding body that has coupling means for coupling with the heel portion of the touring boot and is mounted on the pivot bearing rotatably about the axis of rotation in such a way that, in the downhill position, the coupling means point in a forwards direction in order to engage the heel portion of the touring boot and, in the touring position, the coupling means point in a direction other than the forwards direction, and wherein, in the touring position of the heel unit, in the event of a load with a force component acting perpendicularly to the ski plane being applied by the heel portion of the touring boot to the binding body, the binding body and the base are set up to engage with one another so as to prevent rotation of the binding body about the axis of rotation of the pivot bearing of the base, characterised in that the binding body comprises a flap fastened in particular swivellably to the binding body, which flap is adjustable between an engaged position, in which the flap is engaged with the base, and a decoupled position, in which the flap is not engaged with the base.