diff --git a/Source/CesiumRuntime/Private/Tests/CesiumPropertyTable.spec.cpp b/Source/CesiumRuntime/Private/Tests/CesiumPropertyTable.spec.cpp
index 6f3a89394..5b90f4261 100644
--- a/Source/CesiumRuntime/Private/Tests/CesiumPropertyTable.spec.cpp
+++ b/Source/CesiumRuntime/Private/Tests/CesiumPropertyTable.spec.cpp
@@ -22,7 +22,7 @@ void FCesiumPropertyTableSpec::Define() {
     model = CesiumGltf::Model();
     pExtension =
         &model.addExtension<CesiumGltf::ExtensionModelExtStructuralMetadata>();
-    pExtension->schema = CesiumGltf::Schema();
+    pExtension->schema.emplace();
     pPropertyTable = &pExtension->propertyTables.emplace_back();
   });
 
@@ -42,7 +42,7 @@ void FCesiumPropertyTableSpec::Define() {
     });
 
     It("constructs invalid instance for missing schema", [this]() {
-      pExtension->schema = std::nullopt;
+      pExtension->schema.reset();
 
       FCesiumPropertyTable propertyTable(model, *pPropertyTable);
       TestEqual(
diff --git a/Source/CesiumRuntime/Private/Tests/CesiumPropertyTexture.spec.cpp b/Source/CesiumRuntime/Private/Tests/CesiumPropertyTexture.spec.cpp
index 9007930ae..430a7e3c0 100644
--- a/Source/CesiumRuntime/Private/Tests/CesiumPropertyTexture.spec.cpp
+++ b/Source/CesiumRuntime/Private/Tests/CesiumPropertyTexture.spec.cpp
@@ -34,7 +34,7 @@ void FCesiumPropertyTextureSpec::Define() {
   BeforeEach([this]() {
     model = Model();
     pExtension = &model.addExtension<ExtensionModelExtStructuralMetadata>();
-    pExtension->schema = Schema();
+    pExtension->schema.emplace();
     pPropertyTexture = &pExtension->propertyTextures.emplace_back();
   });
 
@@ -53,7 +53,7 @@ void FCesiumPropertyTextureSpec::Define() {
     });
 
     It("constructs invalid instance for missing schema", [this]() {
-      pExtension->schema = std::nullopt;
+      pExtension->schema.reset();
 
       FCesiumPropertyTexture propertyTexture(model, *pPropertyTexture);
       TestEqual(
diff --git a/extern/cesium-native b/extern/cesium-native
index 2313ce01c..90470470f 160000
--- a/extern/cesium-native
+++ b/extern/cesium-native
@@ -1 +1 @@
-Subproject commit 2313ce01cc567e35588c25795831fb973975e162
+Subproject commit 90470470f6ae26175ffa0f60176c8b9a6353ac48