diff -Naur libnatpmp-20120821.orig/Makefile libnatpmp-20120821/Makefile
--- libnatpmp-20120821.orig/Makefile	2012-08-21 13:24:15.000000000 -0400
+++ libnatpmp-20120821/Makefile	2012-08-26 20:22:40.000000000 -0400
@@ -5,12 +5,13 @@
 # http://miniupnp.free.fr/libnatpmp.html
 
 OS = $(shell uname -s)
-CC = gcc
+CC ?= gcc
 INSTALL = install
 
 # APIVERSION is used in soname
 APIVERSION = 1
 #LDFLAGS = -Wl,--no-undefined
+GENTOO_CFLAGS := $(CFLAGS)
 CFLAGS = -Os
 #CFLAGS = -g -O0
 CFLAGS += -fPIC
@@ -32,6 +33,8 @@
   SONAME = $(SHAREDLIB).$(APIVERSION)
 endif
 
+CFLAGS := $(CFLAGS) $(GENTOO_CFLAGS)
+
 HEADERS = natpmp.h
 
 EXECUTABLES = testgetgateway natpmpc-shared natpmpc-static
@@ -79,19 +82,19 @@
 testgetgateway:	testgetgateway.o getgateway.o
 
 natpmpc-static:	natpmpc.o $(STATICLIB)
-	$(CC) $(LDFLAGS) -o $@ $^
+	$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $^
 
 natpmpc-shared:	natpmpc.o $(SHAREDLIB)
-	$(CC) $(LDFLAGS) -o $@ $^
+	$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $^
 
 $(STATICLIB):	$(LIBOBJS)
 	$(AR) crs $@ $?
 
 $(SHAREDLIB):	$(LIBOBJS)
 ifeq ($(OS), Darwin)
-	$(CC) -dynamiclib -Wl,-install_name,$(SONAME) -o $@ $^
+	$(CC) $(CFLAGS) $(LDFLAGS) -dynamiclib -Wl,-install_name,$(SONAME) -o $@ $^
 else
-	$(CC) -shared -Wl,-soname,$(SONAME) -o $@ $^
+	$(CC) $(CFLAGS) $(LDFLAGS) -shared -Wl,-soname,$(SONAME) -o $@ $^
 endif
 
 # DO NOT DELETE