--- libresample-0.1.3/Makefile.in.orig	2016-07-26 15:40:39 UTC
+++ libresample-0.1.3/Makefile.in
@@ -3,8 +3,8 @@
 # systems, use this file as a template to create a
 # working Makefile.
 
-CC = @CC@
-CFLAGS = @CFLAGS@ -Wall
+CC ?= @CC@
+CFLAGS ?= @CFLAGS@ -Wall
 
 LIBS = @LIBS@ -lm