diff --git a/core/api/src/main/java/org/onlab/onos/cluster/MastershipTerm.java b/core/api/src/main/java/org/onlab/onos/cluster/MastershipTerm.java
index f015ae5..71d08f2 100644
--- a/core/api/src/main/java/org/onlab/onos/cluster/MastershipTerm.java
+++ b/core/api/src/main/java/org/onlab/onos/cluster/MastershipTerm.java
@@ -5,7 +5,7 @@
 public final class MastershipTerm {
 
     private final NodeId master;
-    private int termNumber;
+    private final int termNumber;
 
     private MastershipTerm(NodeId master, int term) {
         this.master = master;