  Conventional fault-tolerant quantum error-correction schemes require a number
of extra qubits that grows linearly with the code's maximum stabilizer
generator weight. For some common distance-three codes, the recent "flag
paradigm" uses just two extra qubits. Chamberland and Beverland (2018) provide
a framework for flag error correction of arbitrary-distance codes. However,
their construction requires conditions that only some code families are known
to satisfy. We give a flag error-correction scheme that works for any
stabilizer code, unconditionally. With fast qubit measurement and reset, it
uses $d+1$ extra qubits for a distance-$d$ code.
