The Feistel construction is a fundamental technique for building pseudorandom permutations and block ciphers. This paper shows that a simple adaptation of the construction is resistant, even to algorithm substitution attacks—that is, adversarial subversion—of the component round functions. Specifically, we establish that a Feistel-based construction with more than \(337n/\log (1/\epsilon )\) rounds can transform a subverted random function—which disagrees with the original one at a small fraction (denoted by \(\epsilon \) ) of inputs—into an object that is crooked-indifferentiable from a random permutation (or ideal cipher), even if the adversary is aware of all the randomness used in the transformation. Here, n denotes the length of both the input and output of the round functions that underlie the Feistel cipher. We also provide a lower bound showing that the construction cannot use fewer than \(2n/\log (1/\epsilon )\) rounds to achieve crooked-indifferentiable security.