diff --git a/makefile b/makefile
index cb4bf00..446cefc 100644
--- a/makefile
+++ b/makefile
@@ -1,4 +1,5 @@
-NUMCORES = ${NUMBER_OF_PROCESSORS}
+NUMCORES = $(shell grep -c "^processor" /proc/cpuinfo)
+NUMCORESWIN = ${NUMBER_OF_PROCESSORS}
 LIBFLAGS = -shared -std=c++11 -O3 -fPIC -Wall
 EXEFLAGS = -Wall -std=c++11 -O3 -Wl,-rpath,'$$ORIGIN/lib'
 LINKEDLIBS = -lgmp -lgmpxx
@@ -30,7 +31,7 @@ libsMulti:
 $(LIBDIR)/libProblem%.a: Source/Problem%.cpp
 	$(CXX) $(LIBFLAGS) -o $@ $< $(LINKEDLIBS)
 libsWindowsMulti:
-	$(MAKE) libsWindows -j $(NUMCORES)
+	$(MAKE) libsWindows -j $(NUMCORESWIN)
 
 #Building the executable
 ProjectEuler: main.cpp