--- libnatpmp-20131126/Makefile.orig	2014-02-14 15:11:03.817984512 +0800
+++ libnatpmp-20131126/Makefile	2014-02-14 15:11:14.132018382 +0800
@@ -23,12 +23,9 @@
 APIVERSION = 1
 #LDFLAGS = -Wl,--no-undefined
 CFLAGS = -Os
-#CFLAGS = -g -O0
-CFLAGS += -fPIC
-CFLAGS += -Wall
-#CFLAGS += -Wextra
-CFLAGS += -DENABLE_STRNATPMPERR
-#CFLAGS += -Wstrict-aliasing
+override CFLAGS += -fPIC
+override CFLAGS += -Wall
+override CFLAGS += -DENABLE_STRNATPMPERR
 
 LIBOBJS = natpmp.o getgateway.o