We introduce a new symmetric measure (called pos ) that utilises the non-symmetric KL cpos 3 measure We can set a threshold for this new measure so that a pair of treebanks can be considered harmonious in their annotation if pos does not surpass the threshold. For the calculation of the threshold, we estimate the effects of (i) the size variation, and (ii) the genre variation in the considered pair of treebanks. The estimations are based on data from treebanks of distinct language families, making the threshold less dependent on the properties of individual languages. We demonstrate the utility of the proposed measure by listing the treebanks in Universal Dependencies version 2.5 (UDv2.5) (Zeman et al., 2019) data that are annotated consistently with other treebanks of the same language. However, the measure could be used to assess inter-treebank annotation consistency under other (non-UD) annotation guidelines as well.