Let $N_{0,r},\dots,N_{m,r}$ be the degree $r$ B-spline basis associated with an ordered extended knot vector, and let \begin{align*} x_1<\dots<x_k \end{align*} lie in $(a,b)$. For any ordered column set and ordered row set satisfying \begin{align*} 0\le i_1<\dots<i_\ell\le m, \qquad 1\le j_1<\dots<j_\ell\le k, \end{align*} the minor \begin{align*} \det\bigl(N_{i_q,r}(x_{j_p})\bigr)_{p,q=1}^{\ell} \end{align*} is nonnegative.