diff --git a/Makefile b/Makefile
index 1bc5d4e..a8a46a9 100644
--- a/Makefile
+++ b/Makefile
@@ -1,28 +1,30 @@
 CXX ?= g++
-CFLAGS = -Wall -Wconversion -O3 -fPIC
+CFLAGS ?= -Wall -Wconversion
+CXXFLAGS ?= $(CFLAGS)
 SHVER = 4
 OS = $(shell uname)
 ifeq ($(OS),Darwin)
-	SHARED_LIB_FLAG = -dynamiclib -Wl,-install_name,libsvm.so.$(SHVER)
+	SHARED_LIB_FLAG = -dynamiclib -Wl,-install_name,libsvm.so.$(SHVER) -fPIC
 else
-	SHARED_LIB_FLAG = -shared -Wl,-soname,libsvm.so.$(SHVER)
+	SHARED_LIB_FLAG = -shared -Wl,-soname,libsvm.so.$(SHVER) -fPIC
 endif
 
 # Uncomment the following lines to enable parallelization with OpenMP
 # CFLAGS += -fopenmp
 # SHARED_LIB_FLAG += -fopenmp
 
-all: svm-train svm-predict svm-scale
+all: svm-train svm-predict svm-scale lib
 
 lib: svm.o
-	$(CXX) $(SHARED_LIB_FLAG) svm.o -o libsvm.so.$(SHVER)
+	$(CXX) $(LDFLAGS) $(SHARED_LIB_FLAG) svm.o -o libsvm.so.$(SHVER)
+	ln -s libsvm.so.$(SHVER) libsvm.so
 svm-predict: svm-predict.c svm.o
-	$(CXX) $(CFLAGS) svm-predict.c svm.o -o svm-predict -lm
+	$(CXX) $(CFLAGS) $(LDFLAGS) svm-predict.c svm.o -o svm-predict -lm
 svm-train: svm-train.c svm.o
-	$(CXX) $(CFLAGS) svm-train.c svm.o -o svm-train -lm
+	$(CXX) $(CFLAGS) $(LDFLAGS) svm-train.c svm.o -o svm-train -lm
 svm-scale: svm-scale.c
-	$(CXX) $(CFLAGS) svm-scale.c -o svm-scale
+	$(CXX) $(CFLAGS) $(LDFLAGS) svm-scale.c -o svm-scale
 svm.o: svm.cpp svm.h
-	$(CXX) $(CFLAGS) -c svm.cpp
+	$(CXX) $(CXXFLAGS) -c svm.cpp
 clean:
 	rm -f *~ svm.o svm-train svm-predict svm-scale libsvm.so.$(SHVER)