diff --git a/helpful-things/Makefile b/helpful-things/Makefile
index 4c2d661..fdff946 100644
--- a/helpful-things/Makefile
+++ b/helpful-things/Makefile
@@ -3,12 +3,13 @@
 
 # The makefile requires gnu make
 
+RESERVED_CPUS?=1
 ifneq ("$(wildcard /proc/cpuinfo)","")
 	processor_count=$(shell grep -c "^processor" /proc/cpuinfo)
 else # Assume FreeBSD for now...
 	processor_count=`sysctl -n kern.smp.cpus`
 endif
-count=$(shell expr $(processor_count) - 1 )
+count=$(shell expr $(processor_count) - $(RESERVED_CPUS) )
 
 __primary: test