diff --git a/src/core/screen-private.h b/src/core/screen-private.h
index e928b612a..246d76e1b 100644
--- a/src/core/screen-private.h
+++ b/src/core/screen-private.h
@@ -69,6 +69,8 @@ typedef enum
 
 struct _MetaScreen
 {
+  GObject parent_instance;
+
   MetaDisplay *display;
   int number;
   char *screen_name;
@@ -139,6 +141,11 @@ struct _MetaScreen
   Window guard_window;
 };
 
+struct _MetaScreenClass
+{
+  GObjectClass parent_class;
+};
+
 MetaScreen*   meta_screen_new                 (MetaDisplay                *display,
                                                int                         number,
                                                guint32                     timestamp);
diff --git a/src/core/screen.c b/src/core/screen.c
index d02536cd8..b44a3adf9 100644
--- a/src/core/screen.c
+++ b/src/core/screen.c
@@ -69,6 +69,27 @@ static void meta_screen_sn_event   (SnMonitorEvent *event,
                                     void           *user_data);
 #endif
 
+G_DEFINE_TYPE (MetaScreen, meta_screen, G_TYPE_OBJECT);
+
+static void
+meta_screen_finalize (GObject *object)
+{
+  /* Actual freeing done in meta_screen_free() for now */
+}
+
+static void
+meta_screen_class_init (MetaScreenClass *klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  object_class->finalize = meta_screen_finalize;
+}
+
+static void
+meta_screen_init (MetaScreen *screen)
+{
+}
+
 static int
 set_wm_check_hint (MetaScreen *screen)
 {
@@ -488,7 +509,7 @@ meta_screen_new (MetaDisplay *display,
       return NULL;
     }
   
-  screen = g_new (MetaScreen, 1);
+  screen = g_object_new (META_TYPE_SCREEN, NULL);
   screen->closing = 0;
   
   screen->display = display;
@@ -718,7 +739,8 @@ meta_screen_free (MetaScreen *screen,
     g_free (screen->xinerama_infos);
   
   g_free (screen->screen_name);
-  g_free (screen);
+
+  g_object_unref (screen);
 
   XFlush (display->xdisplay);
   meta_display_ungrab (display);
@@ -1142,7 +1164,7 @@ meta_screen_remove_workspace (MetaScreen *screen, MetaWorkspace *workspace,
     meta_workspace_activate (neighbour, timestamp);
 
   /* This also removes the workspace from the screens list */
-  meta_workspace_free (workspace);
+  meta_workspace_remove (workspace);
 
   set_number_of_spaces_hint (screen, g_list_length (screen->workspaces));
 
@@ -1236,7 +1258,7 @@ update_num_workspaces (MetaScreen *screen,
       MetaWorkspace *w = tmp->data;
 
       g_assert (w->windows == NULL);
-      meta_workspace_free (w);
+      meta_workspace_remove (w);
       
       tmp = tmp->next;
     }
diff --git a/src/core/workspace-private.h b/src/core/workspace-private.h
index 5b9589ccd..eab39b575 100644
--- a/src/core/workspace-private.h
+++ b/src/core/workspace-private.h
@@ -38,6 +38,7 @@
 
 struct _MetaWorkspace
 {
+  GObject parent_instance;
   MetaScreen *screen;
   
   GList *windows;
@@ -49,6 +50,7 @@ struct _MetaWorkspace
   MetaRectangle *work_area_xinerama;
   GList  *screen_region;
   GList  **xinerama_region;
+  gint n_xinerama_regions;
   GList  *screen_edges;
   GList  *xinerama_edges;
   GSList *all_struts;
@@ -57,8 +59,13 @@ struct _MetaWorkspace
   guint showing_desktop : 1;
 };
 
+struct _MetaWorkspaceClass
+{
+  GObjectClass parent_class;
+};
+
 MetaWorkspace* meta_workspace_new           (MetaScreen    *screen);
-void           meta_workspace_free          (MetaWorkspace *workspace);
+void           meta_workspace_remove        (MetaWorkspace *workspace);
 void           meta_workspace_add_window    (MetaWorkspace *workspace,
                                              MetaWindow    *window);
 void           meta_workspace_remove_window (MetaWorkspace *workspace,
diff --git a/src/core/workspace.c b/src/core/workspace.c
index 625da5087..74d7d184b 100644
--- a/src/core/workspace.c
+++ b/src/core/workspace.c
@@ -45,6 +45,27 @@ static void free_this                    (gpointer candidate,
                                           gpointer dummy);
 static void workspace_free_struts        (MetaWorkspace *workspace);
 
+G_DEFINE_TYPE (MetaWorkspace, meta_workspace, G_TYPE_OBJECT);
+
+static void
+meta_workspace_finalize (GObject *object)
+{
+  /* Actual freeing done in meta_workspace_remove() for now */
+}
+
+static void
+meta_workspace_class_init (MetaWorkspaceClass *klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  object_class->finalize = meta_workspace_finalize;
+}
+
+static void
+meta_workspace_init (MetaWorkspace *workspace)
+{
+}
+
 static void
 maybe_add_to_list (MetaScreen *screen, MetaWindow *window, gpointer data)
 {
@@ -59,7 +80,7 @@ meta_workspace_new (MetaScreen *screen)
 {
   MetaWorkspace *workspace;
 
-  workspace = g_new (MetaWorkspace, 1);
+  workspace = g_object_new (META_TYPE_WORKSPACE, NULL);
 
   workspace->screen = screen;
   workspace->screen->workspaces =
@@ -112,7 +133,7 @@ workspace_free_struts (MetaWorkspace *workspace)
 }
 
 void
-meta_workspace_free (MetaWorkspace *workspace)
+meta_workspace_remove (MetaWorkspace *workspace)
 {
   GList *tmp;
   MetaScreen *screen;
@@ -168,7 +189,7 @@ meta_workspace_free (MetaWorkspace *workspace)
       meta_rectangle_free_list_and_elements (workspace->xinerama_edges);
     }
 
-  g_free (workspace);
+  g_object_unref (workspace);
 
   /* don't bother to reset names, pagers can just ignore
    * extra ones
diff --git a/src/include/screen.h b/src/include/screen.h
index c04bc7b54..3bdcf160a 100644
--- a/src/include/screen.h
+++ b/src/include/screen.h
@@ -23,9 +23,20 @@
 #define META_SCREEN_H
 
 #include <X11/Xlib.h>
-#include <glib.h>
+#include <glib-object.h>
 #include "types.h"
 
+#define META_TYPE_SCREEN            (meta_screen_get_type ())
+#define META_SCREEN(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), META_TYPE_SCREEN, MetaScreen))
+#define META_SCREEN_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass),  META_TYPE_SCREEN, MetaScreenClass))
+#define META_IS_SCREEN(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), META_SCREEN_TYPE))
+#define META_IS_SCREEN_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass),  META_TYPE_SCREEN))
+#define META_SCREEN_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj),  META_TYPE_SCREEN, MetaScreenClass))
+
+typedef struct _MetaScreenClass   MetaScreenClass;
+
+GType meta_screen_get_type (void);
+
 int meta_screen_get_screen_number (MetaScreen *screen);
 MetaDisplay *meta_screen_get_display (MetaScreen *screen);
 
diff --git a/src/include/workspace.h b/src/include/workspace.h
index 00497068c..45ae52157 100644
--- a/src/include/workspace.h
+++ b/src/include/workspace.h
@@ -53,6 +53,17 @@ typedef enum
   META_MOTION_DOWN_RIGHT = -8
 } MetaMotionDirection;
 
+#define META_TYPE_WORKSPACE            (meta_workspace_get_type ())
+#define META_WORKSPACE(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), META_TYPE_WORKSPACE, MetaWorkspace))
+#define META_WORKSPACE_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass),  META_TYPE_WORKSPACE, MetaWorkspaceClass))
+#define META_IS_WORKSPACE(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), META_WORKSPACE_TYPE))
+#define META_IS_WORKSPACE_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass),  META_TYPE_WORKSPACE))
+#define META_WORKSPACE_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj),  META_TYPE_WORKSPACE, MetaWorkspaceClass))
+
+typedef struct _MetaWorkspaceClass   MetaWorkspaceClass;
+
+GType meta_workspace_get_type (void);
+
 int  meta_workspace_index (MetaWorkspace *workspace);
 MetaScreen *meta_workspace_get_screen (MetaWorkspace *workspace);
 void meta_workspace_get_work_area_all_xineramas (MetaWorkspace *workspace,