diff --git a/NewHorizons/External/Configs/PlanetConfig.cs b/NewHorizons/External/Configs/PlanetConfig.cs
index 4a353011..2b071244 100644
--- a/NewHorizons/External/Configs/PlanetConfig.cs
+++ b/NewHorizons/External/Configs/PlanetConfig.cs
@@ -169,6 +169,11 @@ namespace NewHorizons.External.Configs
         /// </summary>
         public WaterModule Water;
 
+        /// <summary>
+        /// Extra data that may be used by extension mods
+        /// </summary>
+        public object extras;
+
         public PlanetConfig()
         {
             // Always have to have a base module
diff --git a/NewHorizons/External/Configs/StarSystemConfig.cs b/NewHorizons/External/Configs/StarSystemConfig.cs
index 2df0dc8c..ce311174 100644
--- a/NewHorizons/External/Configs/StarSystemConfig.cs
+++ b/NewHorizons/External/Configs/StarSystemConfig.cs
@@ -102,6 +102,11 @@ namespace NewHorizons.External.Configs
         /// </summary>
         public CuriosityColorInfo[] curiosities;
 
+        /// <summary>
+        /// Extra data that may be used by extension mods
+        /// </summary>
+        public object extras;
+
         public class NomaiCoordinates
         {
             [MinLength(2)]
diff --git a/SchemaExporter/SchemaExporter.cs b/SchemaExporter/SchemaExporter.cs
index 33c12666..c2e94e25 100644
--- a/SchemaExporter/SchemaExporter.cs
+++ b/SchemaExporter/SchemaExporter.cs
@@ -92,7 +92,7 @@ public static class SchemaExporter
 
             if (_title is "Star System Schema" or "Celestial Body Schema")
             {
-                schema.Properties.Add("extras", new JsonSchemaProperty {
+                schema.Properties["extras"] = new JsonSchemaProperty {
                     Type = JsonObjectType.Object,
                     Description = "Extra data that may be used by extension mods",
                     AllowAdditionalProperties = true,
@@ -100,7 +100,7 @@ public static class SchemaExporter
                     {
                         Type = JsonObjectType.Object
                     }
-                });
+                };
             }
 
             return schema;