diff --git a/ospf6d/Makefile.am b/ospf6d/Makefile.am
index 726ce54..d30ce58 100644
--- a/ospf6d/Makefile.am
+++ b/ospf6d/Makefile.am
@@ -1,6 +1,6 @@
 ## Process this file with automake to produce Makefile.in.
 
-INCLUDES = @INCLUDES@ -I.. -I$(top_srcdir) -I$(top_srcdir)/lib -I$(top_builddir)/lib
+AM_CPPFLAGS = -I.. -I$(top_srcdir) -I$(top_srcdir)/lib -I$(top_builddir)/lib
 DEFS = @DEFS@ -DSYSCONFDIR=\"$(sysconfdir)/\"
 INSTALL_SDATA=@INSTALL@ -m 600