The q-binomial coefficients [nm] = ᴨmi=1(1-qn-m+i)/(1-qi), for integers 0≤m≤n, are known to be polynomials with non-negative integer coefficients. This readily follows from the q-binomial theorem, or the many combinatorial interpretations of [nm]. In this note we conjecture an arithmetically motivated generalisation of the non-negativity property for products of ratios of q-factorials that happen to be polynomials.