diff --git a/Makefile b/Makefile
index 6941b2c..620c56e 100644
--- a/Makefile
+++ b/Makefile
@@ -1,9 +1,9 @@
 PACKAGE	= c99
 VERSION	= 0.0.0
 SUBDIRS	= include src
-RM	= rm -f
-LN	= ln -f
-TAR	= tar -czvf
+RM	?= rm -f
+LN	?= ln -f
+TAR	?= tar -czvf
 
 
 all: subdirs
diff --git a/include/Makefile b/include/Makefile
index 2531d7a..ad4096c 100644
--- a/include/Makefile
+++ b/include/Makefile
@@ -1,10 +1,10 @@
 SUBDIRS	= c99
 PREFIX	= /usr/local
 DESTDIR	=
-RM	= rm -f
-LN	= ln -f
-MKDIR	= mkdir -p
-INSTALL	= install
+RM	?= rm -f
+LN	?= ln -f
+MKDIR	?= mkdir -p
+INSTALL	?= install
 INCLUDEDIR= $(PREFIX)/include
 
 
diff --git a/include/c99/Makefile b/include/c99/Makefile
index 4c46c10..0faa60c 100644
--- a/include/c99/Makefile
+++ b/include/c99/Makefile
@@ -1,9 +1,9 @@
 PREFIX	= /usr/local
 DESTDIR	=
-RM	= rm -f
-LN	= ln -f
-MKDIR	= mkdir -p
-INSTALL	= install
+RM	?= rm -f
+LN	?= ln -f
+MKDIR	?= mkdir -p
+INSTALL	?= install
 INCLUDEDIR= $(PREFIX)/include
 
 
diff --git a/src/Makefile b/src/Makefile
index 643cf83..8d4f700 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -10,10 +10,10 @@ CFLAGSF	= -W `pkg-config --cflags cpp`
 CFLAGS	= -Wall -g -O2 -pedantic
 LDFLAGSF= `pkg-config --libs cpp`
 LDFLAGS	= -L$(PREFIX)/lib -Wl,-rpath,$(PREFIX)/lib
-RM	= rm -f
-LN	= ln -f
-MKDIR	= mkdir -p
-INSTALL	= install
+RM	?= rm -f
+LN	?= ln -f
+MKDIR	?= mkdir -p
+INSTALL	?= install
 
 
 all: subdirs $(TARGETS)
diff --git a/src/target/Makefile b/src/target/Makefile
index ea72e76..88c8657 100644
--- a/src/target/Makefile
+++ b/src/target/Makefile
@@ -8,13 +8,13 @@ CPPFLAGS=
 CFLAGSF	= -W `pkg-config --cflags cpp`
 CFLAGS	= -Wall -g -O2 -fPIC -pedantic
 LDFLAGSF= `pkg-config --libs cpp`
-AR	= ar -rc
-RANLIB	= ranlib
-LD	= $(CC) -shared
-RM	= rm -f
-LN	= ln -f
-MKDIR	= mkdir -p
-INSTALL	= install
+AR	?= ar
+RANLIB	?= ranlib
+CCSHARED?= $(CC) -shared
+RM	?= rm -f
+LN	?= ln -f
+MKDIR	?= mkdir -p
+INSTALL	?= install
 
 
 all: $(TARGETS)
@@ -24,21 +24,21 @@ asm_CFLAGS = $(CPPFLAGSF) $(CPPFLAGS) $(CFLAGSF) $(CFLAGS) `pkg-config --cflags
 asm_LDFLAGS = $(LDFLAGSF) $(LDFLAGS) `pkg-config --libs asm`
 
 asm.so: $(asm_OBJS)
-	$(LD) -o asm.so $(asm_OBJS) $(asm_LDFLAGS)
+	$(CCSHARED) -o asm.so $(asm_OBJS) $(asm_LDFLAGS)
 
 graph_OBJS = graph.o
 graph_CFLAGS = $(CPPFLAGSF) $(CPPFLAGS) $(CFLAGSF) $(CFLAGS)
 graph_LDFLAGS = $(LDFLAGSF) $(LDFLAGS)
 
 graph.so: $(graph_OBJS)
-	$(LD) -o graph.so $(graph_OBJS) $(graph_LDFLAGS)
+	$(CCSHARED) -o graph.so $(graph_OBJS) $(graph_LDFLAGS)
 
 indent_OBJS = indent.o
 indent_CFLAGS = $(CPPFLAGSF) $(CPPFLAGS) $(CFLAGSF) $(CFLAGS)
 indent_LDFLAGS = $(LDFLAGSF) $(LDFLAGS)
 
 indent.so: $(indent_OBJS)
-	$(LD) -o indent.so $(indent_OBJS) $(indent_LDFLAGS)
+	$(CCSHARED) -o indent.so $(indent_OBJS) $(indent_LDFLAGS)
 
 asm.o: asm.c ../../include/c99/target.h ../../config.h
 	$(CC) $(asm_CFLAGS) -c asm.c