diff --git a/new/button_unix.c b/new/button_unix.c
index 986e81d..8ab9aa6 100644
--- a/new/button_unix.c
+++ b/new/button_unix.c
@@ -19,7 +19,13 @@ static void defaultOnClicked(uiControl *c, void *data)
 	// do nothing
 }
 
-// TODO destruction
+static void onDestroy(GtkWidget *widget, gpointer data)
+{
+	struct button *b = (struct button *) data;
+
+	uiFree(b);
+}
+
 uiControl *uiNewButton(const char *text)
 {
 	struct button *b;
@@ -33,6 +39,7 @@ uiControl *uiNewButton(const char *text)
 		NULL);
 
 	widget = GTK_WIDGET(uiControlHandle(b->c));
+	g_signal_connect(widget, "destroy", G_CALLBACK(onDestroy), b);
 	g_signal_connect(widget, "clicked", G_CALLBACK(onClicked), b);
 
 	b->onClicked = defaultOnClicked;
diff --git a/new/container_unix.c b/new/container_unix.c
index 5192639..3a0b517 100644
--- a/new/container_unix.c
+++ b/new/container_unix.c
@@ -15,6 +15,10 @@ static void uiContainer_init(uiContainer *c)
 static void uiContainer_dispose(GObject *obj)
 {
 	g_ptr_array_unref(uiContainer(obj)->children);
+	if (uiContainer(obj)->child != NULL) {
+		uiControlDestroy(uiContainer(obj)->child);
+		uiContainer(obj)->child = NULL;
+	}
 	G_OBJECT_CLASS(uiContainer_parent_class)->dispose(obj);
 }
 
diff --git a/new/newcontrol_unix.c b/new/newcontrol_unix.c
index 673bb81..b424aa6 100644
--- a/new/newcontrol_unix.c
+++ b/new/newcontrol_unix.c
@@ -13,6 +13,11 @@ struct uiSingleWidgetControl {
 
 #define S(c) ((uiSingleWidgetControl *) (c))
 
+static void singleDestroy(uiControl *c)
+{
+	gtk_widget_destroy(S(c)->immediate);
+}
+
 static uintptr_t singleHandle(uiControl *c)
 {
 	return (uintptr_t) (S(c)->widget);
@@ -48,7 +53,12 @@ static void singleResize(uiControl *c, intmax_t x, intmax_t y, intmax_t width, i
 	gtk_widget_size_allocate(S(c)->immediate, &a);
 }
 
-// TODO connect free function
+static void onDestroy(GtkWidget *widget, gpointer data)
+{
+	uiSingleWidgetControl *c = (uiSingleWidgetControl *) data;
+
+	uiFree(c);
+}
 
 uiControl *uiUnixNewControl(GType type, gboolean inScrolledWindow, gboolean needsViewport, gboolean scrolledWindowHasBorder, void *data, const char *firstProperty, ...)
 {
@@ -75,6 +85,19 @@ uiControl *uiUnixNewControl(GType type, gboolean inScrolledWindow, gboolean need
 		c->immediate = c->scrolledWindow;
 	}
 
+	// we need to keep an extra reference on the immediate widget
+	// this is so uiControlDestroy() can work regardless of when it is called and who calls it
+	// without this:
+	// - end user call works (only one ref)
+	// - call in uiContainer destructor fails (uiContainer ref freed)
+	// with this:
+	// - end user call works (shoudn't be in any container)
+	// - call in uiContainer works (both refs freed)
+	g_object_ref_sink(c->immediate);
+	// and let's free the uiSingleWidgetControl with it
+	g_signal_connect(c->immediate, "destroy", G_CALLBACK(onDestroy), c);
+
+	c->control.destroy = singleDestroy;
 	c->control.handle = singleHandle;
 	c->control.setParent = singleSetParent;
 	c->control.preferredSize = singlePreferredSize;
diff --git a/new/window_unix.c b/new/window_unix.c
index 3d6f8e7..293fa51 100644
--- a/new/window_unix.c
+++ b/new/window_unix.c
@@ -8,7 +8,7 @@ struct uiWindow {
 	void *onClosingData;
 };
 
-static void onDestroy(GtkWindow *window, gpointer data)
+static void onDestroy(GtkWidget *widget, gpointer data)
 {
 	uiWindow *w = (uiWindow *) data;