diff --git a/configure.in b/configure.in
index 96cd0ce5..b012de16 100644
--- a/configure.in
+++ b/configure.in
@@ -182,5 +182,6 @@ AC_SUBST(LIBS)
 AC_SUBST(DEBUG)
 AC_SUBST(CFLAGS)
 AC_SUBST(PROFILE)
+AC_SUBST(XIPH_CFLAGS)
 
 AC_OUTPUT(Makefile conf/Makefile src/Makefile src/avl/Makefile src/httpp/Makefile src/thread/Makefile src/log/Makefile src/net/Makefile src/timing/Makefile doc/Makefile web/Makefile win32/Makefile win32/res/Makefile)