diff --git a/core/api/src/main/java/org/onosproject/store/service/AsyncDocumentTree.java b/core/api/src/main/java/org/onosproject/store/service/AsyncDocumentTree.java
index 754366d..136aa6c 100644
--- a/core/api/src/main/java/org/onosproject/store/service/AsyncDocumentTree.java
+++ b/core/api/src/main/java/org/onosproject/store/service/AsyncDocumentTree.java
@@ -113,6 +113,7 @@
      *
      * @param path path to root of subtree to monitor for updates
      * @param listener listener to be notified
+     * @return a future that is completed when the operation completes
      */
     CompletableFuture<Void> addListener(DocumentPath path, DocumentTreeListener<V> listener);
 
@@ -120,6 +121,7 @@
      * Unregisters a previously added listener.
      *
      * @param listener listener to unregister
+     * @return a future that is completed when the operation completes
      */
     CompletableFuture<Void> removeListener(DocumentTreeListener<V> listener);
 
@@ -127,6 +129,7 @@
      * Registers a listener to be notified when the tree is modified.
      *
      * @param listener listener to be notified
+     * @return a future that is completed when the operation completes
      */
     default CompletableFuture<Void> addListener(DocumentTreeListener<V> listener) {
         return addListener(root(), listener);