diff --git a/hippolyzer/lib/base/inventory.py b/hippolyzer/lib/base/inventory.py
index 4d640eb..bc3beaa 100644
--- a/hippolyzer/lib/base/inventory.py
+++ b/hippolyzer/lib/base/inventory.py
@@ -3,6 +3,11 @@ Parse the horrible legacy inventory-related format.
 
 It's typically only used for object contents now.
 """
+
+# TODO: Maybe handle CRC calculation? Does anything care about that?
+#  I don't think anything in the viewer actually looks at the result
+#  of the CRC check for UDP stuff.
+
 from __future__ import annotations
 
 import abc
@@ -451,8 +456,8 @@ class InventoryCategory(InventoryContainerBase):
     pref_type: FolderType = schema_field(SchemaEnumField(FolderType), llsd_name="preferred_type")
     name: str = schema_field(SchemaMultilineStr)
     owner_id: Optional[UUID] = schema_field(SchemaUUID, default=None)
-    version: Optional[int] = schema_field(SchemaInt, default=None)
-    metadata: Optional[Dict[str, Any]] = schema_field(SchemaLLSD, default=None, include_none=True)
+    version: int = schema_field(SchemaInt, default=VERSION_NONE, llsd_only=True)
+    metadata: Optional[Dict[str, Any]] = schema_field(SchemaLLSD, default=None, include_none=False)
 
     __hash__ = InventoryNodeBase.__hash__
 
diff --git a/tests/base/test_legacy_schema.py b/tests/base/test_legacy_schema.py
index 790956d..4d0900c 100644
--- a/tests/base/test_legacy_schema.py
+++ b/tests/base/test_legacy_schema.py
@@ -79,6 +79,9 @@ class TestLegacyInv(unittest.TestCase):
         new_model = InventoryModel.from_str(model.to_str())
         self.assertEqual(model, new_model)
 
+    def test_category_legacy_serialization(self):
+        self.assertEqual(INV_CATEGORY, InventoryModel.from_str(INV_CATEGORY).to_str())
+
     def test_item_access(self):
         item = self.model.nodes[UUID('dd163122-946b-44df-99f6-a6030e2b9597')]
         self.assertEqual(item.name, "New Script")