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. <EOS>