diff --git a/core/api/src/main/java/org/onlab/onos/net/resource/Lambda.java b/core/api/src/main/java/org/onlab/onos/net/resource/Lambda.java
index e09d915..d179d64 100644
--- a/core/api/src/main/java/org/onlab/onos/net/resource/Lambda.java
+++ b/core/api/src/main/java/org/onlab/onos/net/resource/Lambda.java
@@ -33,6 +33,11 @@
         this.lambda = lambda;
     }
 
+    // Constructor for serialization
+    private Lambda() {
+        this.lambda = 0;
+    }
+
     /**
      * Creates a new instance with given lambda.
      *