Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on the safety of the extensions of use of the authorised novel foods (NFs) 2'-fucosyllactose/difucosyllactose (2'-FL/DFL) mixture and lacto- N-tetraose (LNT) in food supplements (FS) for infants pursuant to Regulation (EU) 2015/2283. The NFs are produced by fermentation with genetically modified strains of Escherichia coli K-12 DH1 and already included in the EU list of NF. The applicant stated that no changes in the production process or the identity of the NFs occurred. The applicant proposes an extension of use of the NF containing 2'-FL/DFL mixture in FS intended for infants (< 1 year), at a maximum use level of 1.6 g/day for infants ≤ 6 months and up to 1.2 g/day for infants > 6 months. The applicant also proposes an extension of use of LNT in FS intended for infants (< 1 year), at a maximum use level of 0.8 g/day for infants ≤ 6 months and up to 0.6 g/day for infants > 6 months. The intake per kg body weight of 2'-FL/DFL and LNT from the proposed maximum use levels of the respective NFs in FS for infants does not exceed the lowest estimated mean intake of naturally occurring 2'-FL/DFL and it is similar to the highest estimated mean intake of LNT by breastfed infants. In addition, the Panel notes that the proposed uses of the NFs in FS for infants result in lower maximum daily intakes than those from the already authorised uses of the NFs for the same population group. The Panel concludes that the uses of the NFs containing either 2'-FL/DFL or LNT in FS for infants are safe under the proposed conditions of use.