It is shown that every linear cyclic

-burst-error-correcting code over any finite field can be modified to correct up to

symbols of synchronization slippage without additional redundancy, while maintaining its additive error-correcting capability in the absence of synchronization errors. For codes that are interleaved to a degree

, the synchronization error-correcting capability is

symbols, where

is the length of the burst each subcode corrects. This technique gives an optimum burst-error-correcting code a synchronization error-corecfing capability that is only one symbol short of the known upper bound and is hence asymptotically optimal. Moreover, the implementation is very simple.