Variable-length coding (VLC) is widely used in video coding to improve compression efficiency. However, suffering from loss of synchronization, the VLC bit stream is much more sensitive to random errors than a fixed-length coding (FLC) bit stream. Error-resilient entropy coding (EREC) is a valid tool combating random errors in a VLC bit stream. Due to its intrinsic property of error propagation, when EREC is applied to a video bit stream, those blocks placed later become much more likely to be lost. We propose a simple method to further improve the error robustness of a video bit stream by interleaving transform coefficients of blocks so that low-frequency information is always placed ahead of high-frequency information. Thus, low-frequency information of greater significance is less likely to be lost. Experimental results prove the superiority of the proposed method. In addition, block interleaving can also be used in a data-partitioned video bit stream with ease.