diff --git a/js/ui/panel.js b/js/ui/panel.js
index 006eb3705..dae33b895 100644
--- a/js/ui/panel.js
+++ b/js/ui/panel.js
@@ -181,6 +181,7 @@ const AppMenuButton = new Lang.Class({
         this._targetApp = null;
         this._appMenuNotifyId = 0;
         this._actionGroupNotifyId = 0;
+        this._busyNotifyId = 0;
 
         let bin = new St.Bin({ name: 'appMenu' });
         bin.connect('style-changed', Lang.bind(this, this._onStyleChanged));
@@ -457,12 +458,17 @@ const AppMenuButton = new Lang.Class({
                 this._targetApp.disconnect(this._actionGroupNotifyId);
                 this._actionGroupNotifyId = 0;
             }
+            if (this._busyNotifyId) {
+                this._targetApp.disconnect(this._busyNotifyId);
+                this._busyNotifyId = 0;
+            }
 
             this._targetApp = targetApp;
 
             if (this._targetApp) {
                 this._appMenuNotifyId = this._targetApp.connect('notify::menu', Lang.bind(this, this._sync));
                 this._actionGroupNotifyId = this._targetApp.connect('notify::action-group', Lang.bind(this, this._sync));
+                this._busyNotifyId = this._targetApp.connect('notify::busy', Lang.bind(this, this._sync));
                 this._label.setText(this._targetApp.get_name());
                 this.actor.set_accessible_name(this._targetApp.get_name());
             }
@@ -476,7 +482,7 @@ const AppMenuButton = new Lang.Class({
 
         let isBusy = (this._targetApp != null &&
                       (this._targetApp.get_state() == Shell.AppState.STARTING ||
-                       this._targetApp.get_state() == Shell.AppState.BUSY));
+                       this._targetApp.get_busy()));
         if (isBusy)
             this.startAnimation();
         else
diff --git a/src/shell-app-system.c b/src/shell-app-system.c
index d330975cd..ff838f979 100644
--- a/src/shell-app-system.c
+++ b/src/shell-app-system.c
@@ -335,7 +335,6 @@ _shell_app_system_notify_app_state_changed (ShellAppSystem *self,
   switch (state)
     {
     case SHELL_APP_STATE_RUNNING:
-    case SHELL_APP_STATE_BUSY:
       g_hash_table_insert (self->priv->running_apps, g_object_ref (app), NULL);
       break;
     case SHELL_APP_STATE_STARTING:
diff --git a/src/shell-app.c b/src/shell-app.c
index 2e1262186..a16ef5c8f 100644
--- a/src/shell-app.c
+++ b/src/shell-app.c
@@ -92,6 +92,7 @@ struct _ShellApp
 enum {
   PROP_0,
   PROP_STATE,
+  PROP_BUSY,
   PROP_ID,
   PROP_DBUS_ID,
   PROP_ACTION_GROUP,
@@ -123,6 +124,9 @@ shell_app_get_property (GObject    *gobject,
     case PROP_STATE:
       g_value_set_enum (value, app->state);
       break;
+    case PROP_BUSY:
+      g_value_set_boolean (value, shell_app_get_busy (app));
+      break;
     case PROP_ID:
       g_value_set_string (value, shell_app_get_id (app));
       break;
@@ -678,7 +682,6 @@ shell_app_activate_full (ShellApp      *app,
       case SHELL_APP_STATE_STARTING:
         break;
       case SHELL_APP_STATE_RUNNING:
-      case SHELL_APP_STATE_BUSY:
         shell_app_activate_window (app, NULL, timestamp);
         break;
     }
@@ -1060,22 +1063,27 @@ shell_app_on_ws_switch (MetaScreen         *screen,
   g_signal_emit (app, shell_app_signals[WINDOWS_CHANGED], 0);
 }
 
+gboolean
+shell_app_get_busy (ShellApp *app)
+{
+  if (app->running_state != NULL &&
+      app->running_state->application_proxy != NULL &&
+      shell_org_gtk_application_get_busy (app->running_state->application_proxy))
+    return TRUE;
+
+  return FALSE;
+}
+
 static void
 busy_changed_cb (GObject    *object,
                  GParamSpec *pspec,
                  gpointer    user_data)
 {
-  ShellOrgGtkApplication *proxy;
   ShellApp *app = user_data;
 
-  g_assert (SHELL_IS_ORG_GTK_APPLICATION (object));
   g_assert (SHELL_IS_APP (app));
 
-  proxy = SHELL_ORG_GTK_APPLICATION (object);
-  if (shell_org_gtk_application_get_busy (proxy))
-    shell_app_state_transition (app, SHELL_APP_STATE_BUSY);
-  else
-    shell_app_state_transition (app, SHELL_APP_STATE_RUNNING);
+  g_object_notify (G_OBJECT (app), "busy");
 }
 
 static void
@@ -1097,7 +1105,7 @@ get_application_proxy (GObject      *source,
                         G_CALLBACK (busy_changed_cb),
                         app);
       if (shell_org_gtk_application_get_busy (proxy))
-        shell_app_state_transition (app, SHELL_APP_STATE_BUSY);
+        g_object_notify (G_OBJECT (app), "busy");
     }
 
   if (app->running_state != NULL)
@@ -1577,6 +1585,19 @@ shell_app_class_init(ShellAppClass *klass)
                                                       SHELL_APP_STATE_STOPPED,
                                                       G_PARAM_READABLE));
 
+  /**
+   * ShellApp:busy:
+   *
+   * Whether the application has marked itself as busy.
+   */
+  g_object_class_install_property (gobject_class,
+                                   PROP_BUSY,
+                                   g_param_spec_boolean ("busy",
+                                                         "Busy",
+                                                         "Busy state",
+                                                         FALSE,
+                                                         G_PARAM_READABLE));
+
   /**
    * ShellApp:id:
    *
diff --git a/src/shell-app.h b/src/shell-app.h
index 4cf757286..2916331cb 100644
--- a/src/shell-app.h
+++ b/src/shell-app.h
@@ -30,8 +30,7 @@ struct _ShellAppClass
 typedef enum {
   SHELL_APP_STATE_STOPPED,
   SHELL_APP_STATE_STARTING,
-  SHELL_APP_STATE_RUNNING,
-  SHELL_APP_STATE_BUSY
+  SHELL_APP_STATE_RUNNING
 } ShellAppState;
 
 GType shell_app_get_type (void) G_GNUC_CONST;
@@ -87,6 +86,8 @@ int shell_app_compare (ShellApp *app, ShellApp *other);
 void shell_app_update_window_actions (ShellApp *app, MetaWindow *window);
 void shell_app_update_app_menu       (ShellApp *app, MetaWindow *window);
 
+gboolean shell_app_get_busy          (ShellApp *app);
+
 G_END_DECLS
 
 #endif /* __SHELL_APP_H__ */