--- a/lgmon3/src/Makefile.am	2020-05-13 23:18:47.936735159 +0200
+++ b/lgmon3/src/Makefile.am	2020-05-13 23:19:12.239525072 +0200
@@ -6,6 +6,6 @@
 
 cnijlgmon3_SOURCES = cnijcomif.c cnijifusb.c cnijlgmon3.c cnijifnet.c keytext.c cnijifnet2.c cnijutil.c
 
-CFLAGS = -O2 -Wall -I/usr/include/libusb-1.0 -I./common @XML2_CFLAGS@
+AM_CPPFLAGS = -I/usr/include/libusb-1.0 -I./common @XML2_CFLAGS@
 
 cnijlgmon3_LDADD = -ldl -lusb-1.0 -lcnnet2 -lxml2 -lcnbpcnclapicom2 -lcnbpnet30