diff --git a/bluepy/Makefile b/bluepy/Makefile
index 76bafec..e483aab 100644
--- a/bluepy/Makefile
+++ b/bluepy/Makefile
@@ -10,9 +10,9 @@ IMPORT_SRCS = $(addprefix $(BLUEZ_PATH)/, $(BLUEZ_SRCS))
 LOCAL_SRCS  = bluepy-helper.c
 
 CC = gcc
-CFLAGS = -Os -g -Wall # -Werror
+#CFLAGS = -Os -g -Wall # -Werror ## use CFLAGS passed by OpenWrt
 
-CPPFLAGS = -DHAVE_CONFIG_H
+CPPFLAGS += -DHAVE_CONFIG_H
 ifneq ($(DEBUGGING),)
 CFLAGS += -DBLUEPY_DEBUG=1
 endif