diff --git a/core/api/src/main/java/org/onlab/onos/net/AbstractModel.java b/core/api/src/main/java/org/onlab/onos/net/AbstractModel.java
index e195fde..8c25cda 100644
--- a/core/api/src/main/java/org/onlab/onos/net/AbstractModel.java
+++ b/core/api/src/main/java/org/onlab/onos/net/AbstractModel.java
@@ -9,6 +9,11 @@
 
     private final ProviderId providerId;
 
+    // For serialization
+    public AbstractModel() {
+        providerId = null;
+    }
+
     /**
      * Creates a model entity attributed to the specified provider.
      *