diff --git a/src/highlight.c b/src/highlight.c
index 19aafff..19a9c50 100644
--- a/src/highlight.c
+++ b/src/highlight.c
@@ -3739,6 +3739,7 @@
 	listitem_T	*li;
 	int		i;
 
+	range_list_materialize(pos_list);
 	for (i = 0, li = pos_list->lv_first; li != NULL && i < MAXPOSMATCH;
 							i++, li = li->li_next)
 	{