diff -ru a/Makefile b/Makefile
--- a/Makefile
+++ b/Makefile
@@ -19,30 +19,23 @@
 EXEC=darknet
 OBJDIR=./obj/
 
-CC=gcc
-CPP=g++
+CC?=gcc
+CXX?=g++
 NVCC=nvcc 
 AR=ar
 ARFLAGS=rcs
-OPTS=-Ofast
-LDFLAGS= -lm -pthread 
+LDFLAGS+=${LIBS} -lm -pthread
 COMMON= -Iinclude/ -Isrc/
-CFLAGS=-Wall -Wno-unused-result -Wno-unknown-pragmas -Wfatal-errors -fPIC
+CFLAGS+=${CPPFLAGS} -Wall -Wno-unused-result -Wno-unknown-pragmas -Wfatal-errors
 
 ifeq ($(OPENMP), 1) 
 CFLAGS+= -fopenmp
 endif
 
-ifeq ($(DEBUG), 1) 
-OPTS=-O0 -g
-endif
-
-CFLAGS+=$(OPTS)
-
 ifeq ($(OPENCV), 1) 
 COMMON+= -DOPENCV
 CFLAGS+= -DOPENCV
-LDFLAGS+= `pkg-config --libs opencv` -lstdc++
+LDFLAGS+= `pkg-config --libs opencv` ${CXXFLAGS}
 COMMON+= `pkg-config --cflags opencv` 
 endif
 
@@ -60,8 +53,8 @@
 
 OBJ=gemm.o utils.o cuda.o deconvolutional_layer.o convolutional_layer.o list.o image.o activations.o im2col.o col2im.o blas.o crop_layer.o dropout_layer.o maxpool_layer.o softmax_layer.o data.o matrix.o network.o connected_layer.o cost_layer.o parser.o option_list.o detection_layer.o route_layer.o upsample_layer.o box.o normalization_layer.o avgpool_layer.o layer.o local_layer.o shortcut_layer.o logistic_layer.o activation_layer.o rnn_layer.o gru_layer.o crnn_layer.o demo.o batchnorm_layer.o region_layer.o reorg_layer.o tree.o  lstm_layer.o l2norm_layer.o yolo_layer.o iseg_layer.o image_opencv.o
 EXECOBJA=captcha.o lsd.o super.o art.o tag.o cifar.o go.o rnn.o segmenter.o regressor.o classifier.o coco.o yolo.o detector.o nightmare.o instance-segmenter.o darknet.o
-ifeq ($(GPU), 1) 
-LDFLAGS+= -lstdc++ 
+ifeq ($(GPU), 1)
+LDFLAGS+= ${CXXFLAGS}
 OBJ+=convolutional_kernels.o deconvolutional_kernels.o activation_kernels.o im2col_kernels.o col2im_kernels.o blas_kernels.o crop_layer_kernels.o dropout_layer_kernels.o maxpool_layer_kernels.o avgpool_layer_kernels.o
 endif
 
@@ -83,7 +76,7 @@
 	$(CC) $(CFLAGS) -shared $^ -o $@ $(LDFLAGS)
 
 $(OBJDIR)%.o: %.cpp $(DEPS)
-	$(CPP) $(COMMON) $(CFLAGS) -c $< -o $@
+	$(CXX) $(COMMON) $(CFLAGS) -c $< -o $@
 
 $(OBJDIR)%.o: %.c $(DEPS)
 	$(CC) $(COMMON) $(CFLAGS) -c $< -o $@