# gap is missing the private keyword Low/Info · Three Sigma · NFT perpetuals · 29th January, 2024 Finding 3S-NFTPerp-N03 of the Nftperp Matching Engine security review. - Report: /reports/nftperp-ii - Source: https://cdn.sanity.io/files/qoqld077/production/87f617e82d5468500e950a669f30607376b37c32.pdf --- ### Description The abstract contracts use gaps to change storage later if required, but [AMMRouterBase](https://github.com/nftperp/NFTPerp-V2-Contracts/blob/8ea05fc0ecf299ca8374b571486846652c8725f8/src/AMMRouterBase.sol#L137) is missing the private keyword. ### Status Addressed in [#1b573fa](https://github.com/nftperp/NFTPerp-V2-Contracts/commit/1b573fa605f6e1555ab69d8af1d992390c98bc35) --- Related findings: - [Missing override keyword for interface inherited methods](https://0xsimao.com/findings/m-0-override-keyword-inherited-methods): M^0 Minter Gateway