1 files changed, 2 insertions, 1 deletions
diff --git a/private.h b/private.h
index e6e8210c..16e3f5a6 100644
--- a/private.h
+++ b/private.h
@@ -136,7 +136,8 @@ time_t		  mdoc_atotime(const char *);
 char		 *mdoc_type2a(enum mdoc_type);
 char		 *mdoc_node2a(struct mdoc_node *);
 
-int		  mdoc_valid_pre(struct mdoc *, struct mdoc_node *);
+int		  mdoc_valid_pre(struct mdoc *, 
+			const struct mdoc_node *);
 int		  mdoc_valid_post(struct mdoc *);
 int		  mdoc_action_pre(struct mdoc *, struct mdoc_node *);
 int		  mdoc_action_post(struct mdoc *);