A remark to the definition of Nevanlinna matrices

We prove that the unimodular entire matrix-function
$$\left(
\begin{array}{cc}A(z)&B(z)\\C(z)&D(z)\end{array}
\right)$$
with real entries is a Nevanlinna matrix provided that the three quotients $B/A$, $A/C$, and $D/C$ have positive imaginary part in the upper half-plane.