diff --git a/Makefile b/Makefile
index 5daf5ad7..d4dd53f9 100644
--- a/Makefile
+++ b/Makefile
@@ -60,7 +60,7 @@ else
 CC=gcc
 endif
 
-CPP=g++
+CPP=g++ -std=c++11
 NVCC=nvcc
 OPTS=-Ofast
 LDFLAGS= -lm -pthread
@@ -87,8 +87,8 @@ endif
 ifeq ($(OPENCV), 1)
 COMMON+= -DOPENCV
 CFLAGS+= -DOPENCV
-LDFLAGS+= `pkg-config --libs opencv`
-COMMON+= `pkg-config --cflags opencv`
+LDFLAGS+= `pkg-config --libs opencv4 2> /dev/null || pkg-config --libs opencv`
+COMMON+= `pkg-config --cflags opencv4 2> /dev/null || pkg-config --cflags opencv`
 endif
 
 ifeq ($(OPENMP), 1)