diff --git a/pom.xml b/pom.xml
index e492f54..31a7700 100644
--- a/pom.xml
+++ b/pom.xml
@@ -12,7 +12,7 @@
 
     <groupId>edu.stanford.protege</groupId>
     <artifactId>webprotege-backend-api</artifactId>
-    <version>0.9.5-SNAPSHOT</version>
+    <version>0.9.7</version>
 
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
@@ -76,7 +76,7 @@
         <dependency>
             <groupId>edu.stanford.protege</groupId>
             <artifactId>webprotege-common</artifactId>
-            <version>0.9.4</version>
+            <version>0.9.5</version>
         </dependency>
 
         <dependency>
@@ -106,7 +106,7 @@
         <dependency>
             <groupId>edu.stanford.protege</groupId>
             <artifactId>webprotege-ontology-change</artifactId>
-            <version>0.9.2</version>
+            <version>0.9.3-SNAPSHOT</version>
         </dependency>
 
         <dependency>
diff --git a/src/main/java/edu/stanford/protege/webprotege/event/OntologyBrowserTextChangedEvent.java b/src/main/java/edu/stanford/protege/webprotege/event/OntologyBrowserTextChangedEvent.java
index f605ce5..b561124 100644
--- a/src/main/java/edu/stanford/protege/webprotege/event/OntologyBrowserTextChangedEvent.java
+++ b/src/main/java/edu/stanford/protege/webprotege/event/OntologyBrowserTextChangedEvent.java
@@ -1,5 +1,6 @@
 package edu.stanford.protege.webprotege.event;
 
+import com.fasterxml.jackson.annotation.JsonTypeInfo;
 import com.fasterxml.jackson.annotation.JsonTypeName;
 import edu.stanford.protege.webprotege.common.EventId;
 import edu.stanford.protege.webprotege.common.ProjectEvent;
@@ -19,6 +20,7 @@
  */
 
 @JsonTypeName("webprotege.events.ontologies.OntologyBrowserTextChanged")
+@JsonTypeInfo(use = JsonTypeInfo.Id.CLASS, include = JsonTypeInfo.As.PROPERTY, property = "type")
 public record OntologyBrowserTextChangedEvent(EventId eventId,
                                               ProjectId projectId,
                                               OWLOntologyID ontologyID,
diff --git a/src/main/java/edu/stanford/protege/webprotege/hierarchy/EdgeChange.java b/src/main/java/edu/stanford/protege/webprotege/hierarchy/EdgeChange.java
index 5829cfb..1f20c7b 100644
--- a/src/main/java/edu/stanford/protege/webprotege/hierarchy/EdgeChange.java
+++ b/src/main/java/edu/stanford/protege/webprotege/hierarchy/EdgeChange.java
@@ -1,5 +1,8 @@
 package edu.stanford.protege.webprotege.hierarchy;
 
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import com.fasterxml.jackson.annotation.JsonSubTypes;
+
 import java.util.function.Consumer;
 
 /**
@@ -7,18 +10,29 @@
  * Stanford Center for Biomedical Informatics Research
  * 2021-04-20
  */
+@JsonSubTypes({
+        @JsonSubTypes.Type(AddEdge.class),
+        @JsonSubTypes.Type(RemoveEdge.class)
+})
 public abstract class EdgeChange<U> extends GraphModelChange<U> {
 
-    private final GraphEdge<U> edge;
+
+    private GraphEdge<U> edge;
+
+    protected EdgeChange() {
+
+    }
 
     protected EdgeChange(GraphEdge<U> edge) {
         this.edge = edge;
     }
 
+    @JsonIgnore
     public GraphNode<U> getPredecessor() {
         return edge.getPredecessor();
     }
 
+    @JsonIgnore
     public GraphNode<U> getSuccessor() {
         return edge.getSuccessor();
     }
diff --git a/src/main/java/edu/stanford/protege/webprotege/hierarchy/GraphModelChange.java b/src/main/java/edu/stanford/protege/webprotege/hierarchy/GraphModelChange.java
index e74c94d..cc29d40 100644
--- a/src/main/java/edu/stanford/protege/webprotege/hierarchy/GraphModelChange.java
+++ b/src/main/java/edu/stanford/protege/webprotege/hierarchy/GraphModelChange.java
@@ -12,12 +12,12 @@
  * 2021-04-20
  */
 @JsonSubTypes({
-        @Type(AddEdge.class),
-        @Type(RemoveEdge.class),
+        @Type(EdgeChange.class),
         @Type(AddRootNode.class),
+        @Type(UpdateUserObject.class),
         @Type(RemoveRootNode.class)
 })
-@JsonTypeInfo(use = JsonTypeInfo.Id.NAME, property = "changeType")
+@JsonTypeInfo(use = JsonTypeInfo.Id.NAME, property = "type")
 public abstract class GraphModelChange<U> {
 
     public GraphModelChange() {