diff --git a/core/api/src/main/java/org/onlab/onos/mastership/MastershipEvent.java b/core/api/src/main/java/org/onlab/onos/mastership/MastershipEvent.java
index 7b8531c..9f75fc4 100644
--- a/core/api/src/main/java/org/onlab/onos/mastership/MastershipEvent.java
+++ b/core/api/src/main/java/org/onlab/onos/mastership/MastershipEvent.java
@@ -56,7 +56,10 @@
     }
 
     /**
-     * Returns the NodeID of the node responsible for triggering the event.
+     * Returns the NodeID of the node associated with the event.
+     * For MASTER_CHANGED this is the newly elected master, and for
+     * BACKUPS_CHANGED, this is the node that was newly added, removed, or
+     * whose position was changed in the list.
      *
      * @return node ID as a subject
      */