diff -up ./sample-config/nrpe.cfg.in.include_etc_npre_d ./sample-config/nrpe.cfg.in
--- ./sample-config/nrpe.cfg.in.include_etc_npre_d	2020-03-11 10:40:10.000000000 -0500
+++ ./sample-config/nrpe.cfg.in	2020-04-05 14:25:27.630838557 -0500
--- nrpe.cfg.in	2020-03-11 10:40:10.000000000 -0500
+++ nrpe.cfg.in.new	2020-04-05 14:25:27.630838557 -0500
@@ -362,6 +362,8 @@
 #include_dir=<somedirectory>
 #include_dir=<someotherdirectory>
 
+include_dir=/etc/nrpe.d/
+
 # KEEP ENVIRONMENT VARIABLES
 # This directive allows you to retain specific variables from the environment
 # when starting the NRPE daemon.