diff --git a/examples/kv/kvrun.py b/examples/kv/kvrun.py
index b03b40545..e690151bc 100644
--- a/examples/kv/kvrun.py
+++ b/examples/kv/kvrun.py
@@ -3,13 +3,24 @@
 from kivy.app import App
 from kivy.clock import Clock
 from kivy.lang import Builder
+from kivy.core.window import Window
 
 class KvApp(App):
     def _print_fps(self, *largs):
         print 'FPS: %2.4f (real draw: %d)' % (
             Clock.get_fps(), Clock.get_rfps())
+
+    def _reload_keypress(self, instance, code, *largs):
+        if code != 286:
+            return
+        for child in Window.children[:]:
+            Window.remove_widget(child)
+        root = Builder.load_file(self.options['filename'])
+        Window.add_widget(root)
+
     def build(self):
         Clock.schedule_interval(self._print_fps, 1)
+        Window.bind(on_keyboard=self._reload_keypress)
         return Builder.load_file(self.options['filename'])
 
 if __name__ == '__main__':
diff --git a/kivy/c_ext/graphics.pyx b/kivy/c_ext/graphics.pyx
index 89b0c3f6c..58f75d77d 100644
--- a/kivy/c_ext/graphics.pyx
+++ b/kivy/c_ext/graphics.pyx
@@ -91,10 +91,12 @@ cdef class Canvas:
     cpdef add_canvas(self, Canvas canvas):
         if not canvas in self._children:
             self._children.append(canvas)
+        self._need_compile = 1
 
     cpdef remove_canvas(self, Canvas canvas):
         if canvas in self._children:
             self._children.remove(canvas)
+        self._need_compile = 1
 
     cdef add(self, GraphicInstruction instruction):
         self.need_compile = 1
diff --git a/kivy/uix/widget.py b/kivy/uix/widget.py
index 76165657e..243f84c1d 100644
--- a/kivy/uix/widget.py
+++ b/kivy/uix/widget.py
@@ -336,7 +336,7 @@ class Widget(EventDispatcher):
     children = ListProperty([])
 
     #: Parent
-    parent = ObjectProperty(None)
+    parent = ObjectProperty(None, allownone=True)
 
     #: Size hint X
     size_hint_x = NumericProperty(1, allownone=True)