--- libs/Makefile.lib.common.orig	2019-02-27 16:25:45 UTC
+++ libs/Makefile.lib.common
@@ -1,5 +1,5 @@
 
-CFLAGS += -Wall -O3
+CFLAGS?= -Wall -O3
 
 ifeq ($(DEBUG_POLICY),DEBUG)
 CPPFLAGS += -g # enable for general debugging