A needle unit (2) for a drug delivery device (1), wherein the needle unit (2) comprises a needle (5) which is retractable into the drug delivery device (1) from a starting position to an end position and a needle retainer (3) having a stop member (6).The stop member (6) is configured to prevent a re-exposure of the needle (5) when the needle (5) has been retracted into the drug delivery device (1).
