diff --git a/imm/Imm.cs b/imm/Imm.cs
index 30fc8f1..2653f3c 100644
--- a/imm/Imm.cs
+++ b/imm/Imm.cs
@@ -4,6 +4,7 @@ using System;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Runtime.CompilerServices;
+using System.Text.Json.Serialization;
 
 namespace imm;
 
@@ -51,6 +52,7 @@ public interface Obj<T> : Obj where T : Obj<T>
     /// <summary>
     /// Gets the change delegate associated with this object.
     /// </summary>
+    [JsonIgnore]
     ChangeDelegate<T> OnChange { get; set; }
 
     /// <summary>
@@ -168,7 +170,7 @@ public record class Versioned<T> : Obj<T> where T : Versioned<T>
 {
     public Metadata_Versioned Meta { get; init; } = new();
 
-    [DebuggerBrowsable( DebuggerBrowsableState.Never )]
+    [DebuggerBrowsable( DebuggerBrowsableState.Never )]    
     public ChangeDelegate<T> OnChange { get; set; } = ( o, n ) => { };
 
     public virtual Obj? Old => null;
@@ -179,7 +181,7 @@ public record class Versioned<T> : Obj<T> where T : Versioned<T>
     public Versioned() { }
     protected Versioned( Versioned<T> original )
     {
-        OnChange = original.OnChange;
+        OnChange = original.OnChange; 
         Meta = original.Meta;
     }