diff --git a/lib/rbtree.c b/lib/rbtree.c
index d417556..fe43c8c 100644
--- a/lib/rbtree.c
+++ b/lib/rbtree.c
@@ -387,7 +387,7 @@
 {
 	struct rb_node *parent;
 
-	if (rb_parent(node) == node)
+	if (RB_EMPTY_NODE(node))
 		return NULL;
 
 	/* If we have a right-hand child, go down and then left as far
@@ -416,7 +416,7 @@
 {
 	struct rb_node *parent;
 
-	if (rb_parent(node) == node)
+	if (RB_EMPTY_NODE(node))
 		return NULL;
 
 	/* If we have a left-hand child, go down and then right as far