diff --git a/python/caca/canvas.py b/python/caca/canvas.py
index 292ab87..4373e0e 100644
--- a/python/caca/canvas.py
+++ b/python/caca/canvas.py
@@ -56,17 +56,21 @@ class Canvas(_Canvas):
     """ Canvas object, methods are libcaca functions with canvas_t as
         first parameter.
     """
-    def __init__(self, width=0, height=0):
+    def __init__(self, width=0, height=0, pointer=None):
         """ Canvas constructor.
 
             width   -- the desired canvas width
             height  -- the desired canvas height
+            cv      -- pointer to libcaca canvas
         """
         _lib.caca_create_canvas.argtypes = [ctypes.c_int, ctypes.c_int]
 
-        self._cv = _lib.caca_create_canvas(width, height)
-        if self._cv == 0:
-            raise CanvasError, "Failed to create canvas"
+        if cv is not None:
+            self._cv = _lib.caca_create_canvas(width, height)
+            if self._cv == 0:
+                raise CanvasError, "Failed to create canvas"
+        else:
+            self._cv = cv
 
     def manage(self, *args, **kw):
         """ Not implemented.
@@ -940,7 +944,7 @@ class Canvas(_Canvas):
                 _Canvas, ctypes.c_int, ctypes.c_int, ctypes.c_int, ctypes.c_int,
                 ctypes.c_char_p, p_size_t
         ]
-        _lib.caca_export_area_to_memory.restype  = ctypes.c_void_p
+        _lib.caca_export_area_to_memory.restype  = ctypes.POINTER(ctypes.c_char_p)
 
         p = ctypes.c_size_t()
         ret = _lib.caca_export_area_to_memory(self, x, y, width, height, fmt, p)
diff --git a/python/caca/display.py b/python/caca/display.py
index 451b40a..8bdd887 100644
--- a/python/caca/display.py
+++ b/python/caca/display.py
@@ -17,7 +17,7 @@
 import ctypes
 
 from caca import _lib
-from caca.canvas import _Canvas
+from caca.canvas import _Canvas, Canvas
 
 class _Display(object):
     """ Model for Display objects.
@@ -63,6 +63,9 @@ class Display(_Display):
             ]
             self._dp = _lib.caca_create_display_with_driver(cv, driver)
 
+        if self._dp == 0:
+            raise DisplayError, "Failed to create display"
+
     def get_driver(self):
         """ Return the caca graphical context's current output driver.
         """
@@ -89,8 +92,9 @@ class Display(_Display):
         """ Get the canvas attached to a caca graphical context.
         """
         _lib.caca_get_canvas.argtypes = [_Display]
+        _lib.caca_get_canvas.restype  = ctypes.POINTER(ctypes.c_char_p)
 
-        return _lib.caca_get_canvas(self)
+        return Canvas(pointer=_lib.caca_get_canvas(self))
 
     def refresh(self):
         """ Flush pending changes and redraw the screen.
@@ -194,6 +198,9 @@ class Display(_Display):
 
         return _lib.caca_get_mouse_y(self)
 
+class DisplayError(Exception):
+    pass
+
 class Event(ctypes.Structure):
     """ Object to store libcaca event.
     """