  We consider a numeration system in the ring of integers ${\mathcal O}_K$ of a
number field, which we assume to be principal. We prove that the property of
being a prime in ${\mathcal O}_K$ is decorrelated from two fundamental examples
of automatic sequences relative to the chosen numeration system: the Thue-Morse
and the Rudin-Shapiro sequences. This is an analogue, in ${\mathcal O}_K$, of
results of Mauduit-Rivat which were concerned with the case $K={\mathbb Q}$.
