diff --git a/lib/plist_int.h b/lib/plist_int.h
new file mode 100644
index 0000000..6459579
--- /dev/null
+++ b/lib/plist_int.h
@@ -0,0 +1,71 @@
+/*
+ * Prefix list internal definitions.
+ * Copyright (C) 1999 Kunihiro Ishiguro
+ *
+ * This file is part of GNU Zebra.
+ *
+ * GNU Zebra is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published
+ * by the Free Software Foundation; either version 2, or (at your
+ * option) any later version.
+ *
+ * GNU Zebra is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GNU Zebra; see the file COPYING.  If not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifndef _QUAGGA_PLIST_INT_H
+#define _QUAGGA_PLIST_INT_H
+
+enum prefix_name_type
+{
+  PREFIX_TYPE_STRING,
+  PREFIX_TYPE_NUMBER
+};
+
+struct prefix_list
+{
+  char *name;
+  char *desc;
+
+  struct prefix_master *master;
+
+  enum prefix_name_type type;
+
+  int count;
+  int rangecount;
+
+  struct prefix_list_entry *head;
+  struct prefix_list_entry *tail;
+
+  struct prefix_list *next;
+  struct prefix_list *prev;
+};
+
+/* Each prefix-list's entry. */
+struct prefix_list_entry
+{
+  int seq;
+
+  int le;
+  int ge;
+
+  enum prefix_list_type type;
+
+  int any;
+  struct prefix prefix;
+
+  unsigned long refcnt;
+  unsigned long hitcnt;
+
+  struct prefix_list_entry *next;
+  struct prefix_list_entry *prev;
+};
+
+#endif /* _QUAGGA_PLIST_INT_H */