Nagios NRPE Error: Service check command … not defined …

After installing NRPE on a cluster I saw this error although the service, check_cups in that case, could be executed locally. Other NRPE checks could be executed remotely without errors. After checking the nrpe.cfg file in /etc/nagios I saw the command properly configured:
command[check_cups]=/usr/lib64/nagios/plugins/check_cups -H localhost -T s -w $ARG1$ -c $ARG2$
It took me a while to find out that I have to add this line also to the command-plugins.cfg file in the same folder. After restarting NRPE the output was as expected on the Nagios server.