diff --git a/Sledge.Formats.Map/Formats/JackhamerJmfFormat.cs b/Sledge.Formats.Map/Formats/JackhamerJmfFormat.cs
index 18a360e..0bbe436 100644
--- a/Sledge.Formats.Map/Formats/JackhamerJmfFormat.cs
+++ b/Sledge.Formats.Map/Formats/JackhamerJmfFormat.cs
@@ -67,7 +67,9 @@ private void BuildTree(MapFile map, IEnumerable<JmfGroup> groups, IReadOnlyColle
             var worldspawnEntity = entities.FirstOrDefault(x => x.Entity.ClassName == "worldspawn");
             if (worldspawnEntity != null)
             {
-                map.Worldspawn.SortedProperties = worldspawnEntity.Entity.SortedProperties;
+                var props = worldspawnEntity.Entity.SortedProperties.ToList();
+                map.Worldspawn.SortedProperties.Clear();
+                map.Worldspawn.SortedProperties.AddRange(props);
                 map.Worldspawn.Color = worldspawnEntity.Entity.Color;
                 map.Worldspawn.SpawnFlags = worldspawnEntity.Entity.SpawnFlags;
                 map.Worldspawn.Visgroups = worldspawnEntity.Entity.Visgroups;
diff --git a/Sledge.Formats.Map/Formats/VmfObjects/VmfEntity.cs b/Sledge.Formats.Map/Formats/VmfObjects/VmfEntity.cs
index 27a412a..3036ca8 100644
--- a/Sledge.Formats.Map/Formats/VmfObjects/VmfEntity.cs
+++ b/Sledge.Formats.Map/Formats/VmfObjects/VmfEntity.cs
@@ -51,9 +51,9 @@ public override MapObject ToMapObject()
             var ent = new Entity
             {
                 ClassName = ClassName,
-                SpawnFlags = SpawnFlags,
-                SortedProperties = new List<KeyValuePair<string, string>>(Properties)
+                SpawnFlags = SpawnFlags
             };
+            ent.SortedProperties.AddRange(Properties);
 
             Editor.Apply(ent);
 
diff --git a/Sledge.Formats.Map/Objects/Entity.cs b/Sledge.Formats.Map/Objects/Entity.cs
index aafd56e..37ad723 100644
--- a/Sledge.Formats.Map/Objects/Entity.cs
+++ b/Sledge.Formats.Map/Objects/Entity.cs
@@ -9,7 +9,7 @@ public class Entity : MapObject
     {
         public string ClassName { get; set; }
         public int SpawnFlags { get; set; }
-        public List<KeyValuePair<string, string>> SortedProperties { get; set; }
+        public List<KeyValuePair<string, string>> SortedProperties { get; }
         public IDictionary<string, string> Properties { get; }
 
         public Entity()