diff --git a/Makefile b/Makefile
index 9d70e795..a51ea30b 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
-CXX=		g++
-CC=			gcc
-CXXFLAGS=	-g -O3 -msse4.2 -mpopcnt -fomit-frame-pointer -Wall
-CFLAGS=		$(CXXFLAGS)
+CXX ?=	g++
+CC  ?=	gcc
+CXXFLAGS ?= $(CXXFLAGS)	-g -O3 -msse4.2 -mpopcnt -fomit-frame-pointer -Wall
+CFLAGS ?= $(CXXFLAGS)
 CPPFLAGS=
 INCLUDES=
 OBJS=		CommandLines.o Process_Read.o Assembly.o Hash_Table.o \
@@ -79,4 +79,4 @@ tovlp.o: tovlp.h
 inter.o: inter.h Process_Read.h
 kalloc.o: kalloc.h
 gfa_ut.o: Overlaps.h
-gchain_map.o: gchain_map.h
\ No newline at end of file
+gchain_map.o: gchain_map.h