diff --git a/docs/docsite/Makefile b/docs/docsite/Makefile
index 2f1408f17d..5d03e2b3c6 100644
--- a/docs/docsite/Makefile
+++ b/docs/docsite/Makefile
@@ -1,7 +1,8 @@
+OS = $(shell uname -s)
 SITELIB = $(shell python -c "from distutils.sysconfig import get_python_lib; print get_python_lib()"):
 FORMATTER=../../hacking/module_formatter.py
 DUMPER=../../hacking/dump_playbook_attributes.py
-ifeq ($(shell echo $(OS) | egrep -c 'Darwin|FreeBSD|OpenBSD|DragonFly'),1)
+ifeq ($(shell echo $(OS) | egrep -ic 'Darwin|FreeBSD|OpenBSD|DragonFly'),1)
 CPUS := $(shell sysctl hw.ncpu|awk '{print $2}')
 else
 CPUS := $(shell nproc)