diff --git a/output/Makefile.am b/output/Makefile.am
index 630aee6..61d827a 100644
--- a/output/Makefile.am
+++ b/output/Makefile.am
@@ -1,4 +1,4 @@
-AM_CPPFLAGS = -I$(top_srcdir)/include
+AM_CPPFLAGS = -I$(top_srcdir)/include ${LIBNETFILTER_ACCT_CFLAGS}
 AM_CFLAGS = ${regular_CFLAGS} ${LIBNETFILTER_LOG_CFLAGS} \
 	    ${LIBNETFILTER_CONNTRACK_CFLAGS}