--- Makefile.orig	2021-04-16 08:52:40 UTC
+++ Makefile
@@ -29,7 +29,8 @@
 
 CC		= gcc
 COMPRESS 	= gzip -n
-CFLAGS		+= -O2 -g -W -Wall -Werror -pthread $(CPPFLAGS)
+CFLAGS		?= -O2 -g -W -Wall -Werror
+CFLAGS		+= -pthread $(CPPFLAGS)
 PKG_CONFIG 	= pkg-config
 STRIP 		= -s
 INSTALL 	= install
@@ -101,7 +102,7 @@ $(OBJDIR)%.o: %.c Makefile airscan.h
 
 .PHONY: all clean install man
 
-all:	tags $(BACKEND) $(DISCOVER) test test-decode test-multipart test-zeroconf test-uri
+all:	$(BACKEND) $(DISCOVER) test test-decode test-multipart test-zeroconf test-uri
 
 tags: $(SRC) airscan.h test.c test-decode.c test-multipart.c test-zeroconf.c test-uri.c
 	-ctags -R .