diff --git a/filament/src/Engine.cpp b/filament/src/Engine.cpp
index 0a87b2503e0..fb4ad59c9e6 100644
--- a/filament/src/Engine.cpp
+++ b/filament/src/Engine.cpp
@@ -325,6 +325,11 @@ void FEngine::prepare() {
             item->commit(*this);
         }
     }
+
+    // Commit default material instances.
+    for (auto& material : mMaterials) {
+        material->getDefaultInstance()->commit(*this);
+    }
 }
 
 void FEngine::gc() {
diff --git a/filament/src/MaterialInstance.cpp b/filament/src/MaterialInstance.cpp
index 4646ca223d5..bc4902167a8 100644
--- a/filament/src/MaterialInstance.cpp
+++ b/filament/src/MaterialInstance.cpp
@@ -69,7 +69,7 @@ void FMaterialInstance::initDefaultInstance(FEngine& engine, FMaterial const* ma
 
     if (!material->getUniformInterfaceBlock().isEmpty()) {
         mUniforms = UniformBuffer(material->getUniformInterfaceBlock());
-        mUbHandle = driver.createUniformBuffer(mUniforms.getSize(), driver::BufferUsage::STATIC);
+        mUbHandle = driver.createUniformBuffer(mUniforms.getSize(), driver::BufferUsage::DYNAMIC);
     }
 
     if (!material->getSamplerInterfaceBlock().isEmpty()) {