diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 4900f182e99d..d0ae808f3a14 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -3447,9 +3447,20 @@ static inline void mas_root_expand(struct ma_state *mas, void *entry)
 	return;
 }
 
+/*
+ * mas_store_root() - Storing value into root.
+ * @mas: The maple state
+ * @entry: The entry to store.
+ *
+ * There is no root node now and we are storing a value into the root - this
+ * function either assigns the pointer or expands into a node.
+ */
 static inline void mas_store_root(struct ma_state *mas, void *entry)
 {
-	if (likely((mas->last != 0) || (mas->index != 0)))
+	if (!entry) {
+		if (!mas->index)
+			rcu_assign_pointer(mas->tree->ma_root, NULL);
+	} else if (likely((mas->last != 0) || (mas->index != 0)))
 		mas_root_expand(mas, entry);
 	else if (((unsigned long) (entry) & 3) == 2)
 		mas_root_expand(mas, entry);