diff --git a/ScreenUi.cpp b/ScreenUi.cpp
index 7ed03d5..fad4e79 100644
--- a/ScreenUi.cpp
+++ b/ScreenUi.cpp
@@ -124,7 +124,9 @@ Container::Container() {
 }
 
 Container::~Container() {
-  free(components_);
+  if (components_) {
+    free(components_);
+  }
 }
 
 void Container::update(Screen *screen) {
@@ -154,11 +156,7 @@ void Container::repaint() {
 void Container::add(Component *component, int8_t x, int8_t y) {
   if (!components_ || componentsLength_ <= componentCount_) {
     uint8_t newComponentsLength = (componentsLength_ * 2) + 1;
-    Component** newComponents = (Component**) malloc(newComponentsLength * sizeof(Component*));
-    for (int i = 0; i < componentCount_; i++) {
-      newComponents[i] = components_[i];
-    }
-    free(components_);
+    Component** newComponents = (Component**) realloc(newComponentsLength * sizeof(Component*));
     components_ = newComponents;
     componentsLength_ = newComponentsLength;
   }
@@ -354,6 +352,10 @@ List::List(uint8_t maxItems) : Label(NULL) {
   captured_ = false;
 }
 
+List::~List() {
+  free(items_);
+}
+
 void List::addItem(const char *item) {
   items_[itemCount_++] = (char*) item;
   if (text_ == NULL) {
diff --git a/ScreenUi.h b/ScreenUi.h
index 06a43e9..661910b 100644
--- a/ScreenUi.h
+++ b/ScreenUi.h
@@ -53,7 +53,7 @@ class CharSet {
 class RangeCharSet : public CharSet {
   public:
     RangeCharSet(int rangeCount, ...);
-    ~RangeCharSet();
+    virtual ~RangeCharSet();
     virtual int charAt(int index);
     virtual unsigned char size();
   private:
@@ -125,7 +125,7 @@ class Component {
 class Container : public Component {
   public:
     Container();
-    ~Container();
+    virtual ~Container();
     virtual void add(Component *component, int8_t x, int8_t y);
     virtual void update(Screen *screen);
     // Paints any dirty child components.
@@ -258,6 +258,7 @@ class Checkbox : public Label {
 class List : public Label {
   public:
     List(uint8_t maxItems);
+    virtual ~List();
     void addItem(const char *item);
     const char *selectedItem() { return items_[selectedIndex_]; }
     uint8_t selectedIndex() { return selectedIndex_; }
@@ -333,7 +334,7 @@ class ScrollContainer : public Container {
     // better than adding this property to every other object or walking
     // the tree to find it.
     ScrollContainer(Screen *screen, uint8_t width, uint8_t height);
-    ~ScrollContainer();
+    virtual ~ScrollContainer();
     virtual void paint(Screen *screen);
     virtual bool dirty();
     #ifdef SCREENUI_DEBUG