diff --git a/Sketch3D/private/Sketch3D.cpp b/Sketch3D/private/Sketch3D.cpp
index 183036b..f366d47 100644
--- a/Sketch3D/private/Sketch3D.cpp
+++ b/Sketch3D/private/Sketch3D.cpp
@@ -280,7 +280,7 @@ void PencilBrush::draw(Renderer* render, const Camera* camera) {
 }
 
 PencilBrush::~PencilBrush() {
-	if (mStroke) delete mStroke;
+	delete mStroke;
 }
 
 void PencilBrush::finish(Project* proj) {
diff --git a/Widgets/private/managers/UpdateManager.cpp b/Widgets/private/managers/UpdateManager.cpp
index 5d15414..aeacc42 100644
--- a/Widgets/private/managers/UpdateManager.cpp
+++ b/Widgets/private/managers/UpdateManager.cpp
@@ -160,8 +160,10 @@ void UpdateManager::processActiveTree(Widget* iter, EventHandler& events, Vec2F
 		procWidget(iter, events, false);
 	}
 
-	for (auto child : iter->mDepthOrder) {
-		processActiveTree(child.data(), events, current);
+	for (auto child = iter->mDepthOrder.firstNode(); child;) {
+		auto next = child->next; // any child may be removed at runtime
+		processActiveTree(child->data, events, current);
+		child = next;
 	}
 }