This paper presents a PDF-matched modification to Stone’s measure of predictability. The modified measure of predictability is a measure of non-gaussianity too. It is an extent of signal predictability by two different prediction terms. One prediction term is based on a normal gaussian PDF assumption for signal. In contrast, the other one is based on a unit variance supergaussian PDF assumption for signal. By contrastive deployment of the above prediction terms, the modified measure of predictability enables BSS to follow a high kurtosis PDF assumption for signals. As an advantage, not only signals with maximized predictability are recovered, but also with increased non-gaussianity too. Deploying the modified measure of predictability concludes more independent recovered signals. The dominance of BSS based on the modified measure to the previous one has been demonstrated by many tests performed over mixtures of realistic audio signals (music and speech) and over mixtures of gray-scale images.