A cap for closing a spout of a neck of a package, comprising a sidewall being provided with inner threads for engagement with corresponding outer threads of the neck, and an inner top surface forming a closing surface for the spout, wherein the sidewall has an uppermost portion connecting to the inner top surface, said uppermost portion comprising a guiding structure, wherein the guiding structure is formed by an inner surface of the sidewall being tilted radially inwards, the guiding structure extending from a vertical portion of the sidewall, wherein the guiding structure further comprises a depression forming a stop for the spout, and the cap further comprising a sealing lip arranged radially inwards of the guiding structure, the guiding structure is formed by an inner surface of the sidewall being tilted radially inwards, in a direction towards the inner top surface, the guiding structure, i.e. the inner surface, extends from a vertical portion of the sidewall towards the inner top surface, characterized in that the sealing lip has a bead extending radially outwards for further increasing the contact, and hence the sealing action, between the cap and the neck, the depression is arranged between the sealing lip and the guiding structure, the depression is located between the inner top surface and the tilted inner surface and dimensioned to receive an upper end of the spout and to form a stop, for preventing further movement of the cap relative the spout, the depression extending in a radial direction from the sealing lip to the end of the tilted inner surface, the tilted inner surface ends slightly before it reaches the inner top surface, and the tilting angle (α) of at least a part of the guiding structure is constant. a sidewall being provided with inner threads for engagement with corresponding outer threads of the neck, and an inner top surface forming a closing surface for the spout, wherein the sidewall has an uppermost portion connecting to the inner top surface, said uppermost portion comprising a guiding structure, wherein the guiding structure is formed by an inner surface of the sidewall being tilted radially inwards, the guiding structure extending from a vertical portion of the sidewall, wherein the guiding structure further comprises a depression forming a stop for the spout, and the cap further comprising a sealing lip arranged radially inwards of the guiding structure, the guiding structure is formed by an inner surface of the sidewall being tilted radially inwards, in a direction towards the inner top surface, the guiding structure, i.e. the inner surface, extends from a vertical portion of the sidewall towards the inner top surface, characterized in that the sealing lip has a bead extending radially outwards for further increasing the contact, and hence the sealing action, between the cap and the neck, the depression is arranged between the sealing lip and the guiding structure, the depression is located between the inner top surface and the tilted inner surface and dimensioned to receive an upper end of the spout and to form a stop, for preventing further movement of the cap relative the spout, the depression extending in a radial direction from the sealing lip to the end of the tilted inner surface, the tilted inner surface ends slightly before it reaches the inner top surface, and the tilting angle (α) of at least a part of the guiding structure is constant.