diff --git a/SabreTools.Core/BaseFirstContractResolver.cs b/SabreTools.Core/BaseFirstContractResolver.cs
deleted file mode 100644
index 40bd6293..00000000
--- a/SabreTools.Core/BaseFirstContractResolver.cs
+++ /dev/null
@@ -1,33 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-
-using Newtonsoft.Json;
-using Newtonsoft.Json.Serialization;
-
-namespace SabreTools.Core
-{
-    // https://github.com/dotnet/runtime/issues/728
-    public class BaseFirstContractResolver : DefaultContractResolver
-    {
-        public BaseFirstContractResolver()
-        {
-            NamingStrategy = new CamelCaseNamingStrategy();
-        }
-
-        protected override IList<JsonProperty> CreateProperties(Type type, MemberSerialization memberSerialization)
-        {
-            return base.CreateProperties(type, memberSerialization)
-                .OrderBy(p => BaseTypesAndSelf(p.DeclaringType).Count()).ToList();
-
-            IEnumerable<Type> BaseTypesAndSelf(Type t)
-            {
-                while (t != null)
-                {
-                    yield return t;
-                    t = t.BaseType;
-                }
-            }
-        }
-    }
-}
diff --git a/SabreTools.DatFiles/DatFiles/SabreJSON.cs b/SabreTools.DatFiles/DatFiles/SabreJSON.cs
index cebf6e72..43ef459e 100644
--- a/SabreTools.DatFiles/DatFiles/SabreJSON.cs
+++ b/SabreTools.DatFiles/DatFiles/SabreJSON.cs
@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
+using System.Linq;
 using System.Text;
 
 using SabreTools.Core;
@@ -8,6 +9,7 @@ using SabreTools.Core.Tools;
 using SabreTools.DatItems;
 using Newtonsoft.Json;
 using Newtonsoft.Json.Linq;
+using Newtonsoft.Json.Serialization;
 
 namespace SabreTools.DatFiles
 {
@@ -520,5 +522,29 @@ namespace SabreTools.DatFiles
 
             jtw.Flush();
         }
+    
+        // https://github.com/dotnet/runtime/issues/728
+        private class BaseFirstContractResolver : DefaultContractResolver
+        {
+            public BaseFirstContractResolver()
+            {
+                NamingStrategy = new CamelCaseNamingStrategy();
+            }
+
+            protected override IList<JsonProperty> CreateProperties(Type type, MemberSerialization memberSerialization)
+            {
+                return base.CreateProperties(type, memberSerialization)
+                    .OrderBy(p => BaseTypesAndSelf(p.DeclaringType).Count()).ToList();
+
+                IEnumerable<Type> BaseTypesAndSelf(Type t)
+                {
+                    while (t != null)
+                    {
+                        yield return t;
+                        t = t.BaseType;
+                    }
+                }
+            }
+        }
     }
 }