diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index df352f6ccc240979f2fb03b9f096e4afc579a8cc..3fe1491d2bf985c157409e7722476486e0ac59ac 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -323,14 +323,19 @@ static inline void *mte_safe_root(const struct maple_enode *node)
 	return (void *)((unsigned long)node & ~MAPLE_ROOT_NODE);
 }
 
-static inline void mte_set_full(const struct maple_enode *node)
+static inline void *mte_set_full(const struct maple_enode *node)
 {
-	node = (void *)((unsigned long)node & ~MAPLE_ENODE_NULL);
+	return (void *)((unsigned long)node & ~MAPLE_ENODE_NULL);
 }
 
-static inline void mte_clear_full(const struct maple_enode *node)
+static inline void *mte_clear_full(const struct maple_enode *node)
 {
-	node = (void *)((unsigned long)node | MAPLE_ENODE_NULL);
+	return (void *)((unsigned long)node | MAPLE_ENODE_NULL);
+}
+
+static inline bool mte_has_null(const struct maple_enode *node)
+{
+	return (unsigned long)node & MAPLE_ENODE_NULL;
 }
 
 static inline bool ma_is_root(struct maple_node *node)