diff --git a/src/core/store/serialize.ts b/src/core/store/serialize.ts
index 8adc27c6..450468d2 100644
--- a/src/core/store/serialize.ts
+++ b/src/core/store/serialize.ts
@@ -84,6 +84,7 @@ import {
 import { type FlatItem, makeFlatItem } from '../properties/listItems';
 import {
   coerceValue,
+  initialOf,
   isValidFieldName,
   isValidVariableName,
   type PropertyDef,
@@ -771,7 +772,9 @@ function normalizeBag(raw: unknown, schema: PropertySchema, sparse: boolean): Pr
   for (const def of schema) {
     const value = r[def.key];
     if (value === undefined || value === null) {
-      if (!sparse) bag[def.key] = def.default;
+      // A key with its own `initial` stays missing: written out, the old reading would count as
+      // a deviation from what a new asset starts with, and mark every older asset gold.
+      if (!sparse && initialOf(def) === def.default) bag[def.key] = def.default;
       continue;
     }
     bag[def.key] = coerceValue(def, value as PropertyValue);
diff --git a/tests/core/serialize.test.ts b/tests/core/serialize.test.ts
index 1c0f1e1d..fd08acb3 100644
--- a/tests/core/serialize.test.ts
+++ b/tests/core/serialize.test.ts
@@ -177,7 +177,6 @@ describe('serialize', () => {
       rotation: 0,
       mirrorX: false,
       mirrorY: false,
-      sortWithParent: false,
       width: 10,
       height: 100,
       color: 0xffffff,
diff --git a/tests/viewport/sort-with-parent.test.ts b/tests/viewport/sort-with-parent.test.ts
index ca613f09..aa079ab0 100644
--- a/tests/viewport/sort-with-parent.test.ts
+++ b/tests/viewport/sort-with-parent.test.ts
@@ -65,6 +65,9 @@ describe('a child sorted with its parent (#232)', () => {
     delete weapon.props[SORT_WITH_PARENT_KEY];
     const loaded = findAsset(roundTrip(s.f.project), s.weaponId)!;
     expect(resolveAssetProps(s.f.project, loaded)[SORT_WITH_PARENT_KEY]).toBe(false);
+    // Loading must not write the old reading out, or every older asset would be marked.
+    expect(loaded.props[SORT_WITH_PARENT_KEY]).toBeUndefined();
+    expect(isModified(s.f.project, loaded, SORT_WITH_PARENT_KEY)).toBe(false);
   });
 
   it('marks an asset only once it is switched off, and Reset switches it on again', () => {