The Human Tissue Authority has very recently posted seven new Codes of Practice to update its guidance on human tissue legislation. Code G - Donation of Allogeneic Bone Marrow and Peripheral Blood Stem Cells for Transplantation - aims to improve the regulation of offences, referrals, and the interview process for children donating bone marrow. Code G comes under criticism in this article for not properly taking into account the welfare of very young saviour siblings. It introduces minor changes to consent procedures but disappointingly, parents of saviour siblings can still enjoy significant discretion to consent to a potentially harmful trespass upon their child without a welfare test or court approval. This article suggests that a stronger emphasis should be placed upon the objective provisions of the welfare test under section 1(3) of the Children Act 1989 and its adjoining common law before a decision to harvest a very young child for bone marrow is made. This would better protect the “saviour sibling” from unnecessary physical and psychiatric harm.