diff --git a/src/ftxui/component/container.cpp b/src/ftxui/component/container.cpp
index 1948a47d..410bb9f5 100644
--- a/src/ftxui/component/container.cpp
+++ b/src/ftxui/component/container.cpp
@@ -163,6 +163,7 @@ class VerticalContainer : public ContainerBase {
       return false;
     }
 
+    int old_selected = *selector_;
     if (event.mouse().button == Mouse::WheelUp) {
       MoveSelector(-1);
     }
@@ -171,7 +172,7 @@ class VerticalContainer : public ContainerBase {
     }
     *selector_ = std::max(0, std::min(int(children_.size()) - 1, *selector_));
 
-    return true;
+    return old_selected != *selector_;
   }
 
   Box box_;
diff --git a/src/ftxui/dom/flex.cpp b/src/ftxui/dom/flex.cpp
index 2fd3adf6..b6f95c6e 100644
--- a/src/ftxui/dom/flex.cpp
+++ b/src/ftxui/dom/flex.cpp
@@ -80,6 +80,7 @@ class Flex : public Node {
   }
 
   void SetBox(Box box) override {
+    Node::SetBox(box);
     if (children_.empty()) {
       return;
     }