kc3-lang/kc3

diff --git a/libc3/window/sdl2/demo/configure b/libc3/window/sdl2/demo/configure
index f6ed10f..57be739 100755
--- a/libc3/window/sdl2/demo/configure
+++ b/libc3/window/sdl2/demo/configure
@@ -44,7 +44,7 @@ OBJECTS_DEBUG="$(c2ext .debug.lo "$SOURCES")"
 echo "OBJECTS_DEBUG = $OBJECTS_DEBUG" >> ${CONFIG_MK}
 
 # Common config for all targets
-CPPFLAGS="$CPPFLAGS -I../../../../libffi/include -I../../../.."
+CPPFLAGS="-I../../../../libffi/include -I../../../.. $CPPFLAGS"
 CPPFLAGS="$CPPFLAGS -DGL_SILENCE_DEPRECATION=1"
 CFLAGS="$CFLAGS -W -Wall -Werror -std=c99 -pedantic"
 LIBS="$LIBS"