--- src/makefile.orig	2018-09-01 09:01:40 UTC
+++ src/makefile
@@ -2,9 +2,9 @@
 # Linux makefile
 #
 
-CFLAGS=`sdl-config --cflags`
+CFLAGS+=`sdl-config --cflags`
 PREFIX=../linux/
 SUFFIX=
-LIBS=`sdl-config --libs`
+LIBS+=`sdl-config --libs`
 
 include makefile.common