diff --git a/Makefile b/Makefile
index 5160e83..c962572 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 PKG_CONFIG ?= pkg-config
-CXXFLAGS := -std=gnu++14 -O2 -Wall -I. -g $(shell $(PKG_CONFIG) libusb-1.0 --cflags) -pthread
-LDFLAGS := $(shell $(PKG_CONFIG) libusb-1.0 --libs) -pthread
+CXXFLAGS := -std=gnu++14 -O2 -Wall -I. -g $(shell $(PKG_CONFIG) libusb-1.0 --cflags) -pthread $(CXXFLAGS)
+LDFLAGS := $(shell $(PKG_CONFIG) libusb-1.0 --libs) -pthread $(LDFLAGS)
 AR := ar
 LN := ln
 RANLIB := ranlib