diff --git a/tests/serialization/scene-document-json.test.ts b/tests/serialization/scene-document-json.test.ts
index 8fc7cb7b..e8f6a106 100644
--- a/tests/serialization/scene-document-json.test.ts
+++ b/tests/serialization/scene-document-json.test.ts
@@ -83,6 +83,7 @@ describe("scene document JSON", () => {
       version: 1,
       name: "Foundation Scene",
       world: createEmptySceneDocument().world,
+      materials: {},
       textures: {},
       assets: {},
       brushes: {},