diff --git a/gtk/gtkappchooserdialog.c b/gtk/gtkappchooserdialog.c
index 8d03cc00c9..c0ee59ceaa 100644
--- a/gtk/gtkappchooserdialog.c
+++ b/gtk/gtkappchooserdialog.c
@@ -80,6 +80,7 @@ struct _GtkAppChooserDialogPrivate {
   GCancellable *online_cancellable;
 
   gboolean show_more_clicked;
+  gboolean dismissed;
 };
 
 enum {
@@ -129,6 +130,9 @@ search_for_mimetype_ready_cb (GObject      *source,
 
   _gtk_app_chooser_online_search_for_mimetype_finish (online, res, &error);
 
+  if (self->priv->dismissed)
+    goto out;
+
   if (error != NULL &&
       !g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
     {
@@ -141,7 +145,9 @@ search_for_mimetype_ready_cb (GObject      *source,
       gtk_app_chooser_refresh (GTK_APP_CHOOSER (self->priv->app_chooser_widget));
     }
 
+ out:
   g_clear_error (&error);
+  g_object_unref (self);
 
   gdk_threads_leave ();
 }
@@ -160,7 +166,7 @@ online_button_clicked_cb (GtkButton *b,
 						     GTK_WINDOW (self),
                                                      self->priv->online_cancellable,
 						     search_for_mimetype_ready_cb,
-						     self);
+						     g_object_ref (self));
 }
 
 static void
@@ -174,7 +180,8 @@ app_chooser_online_get_default_ready_cb (GObject *source,
 
   self->priv->online = _gtk_app_chooser_online_get_default_finish (source, res);
 
-  if (self->priv->online != NULL)
+  if (self->priv->online != NULL &&
+      !self->priv->dismissed)
     {
       GtkWidget *action_area;
 
@@ -194,13 +201,16 @@ app_chooser_online_get_default_ready_cb (GObject *source,
       gtk_widget_show (self->priv->online_button);
     }
 
+  g_object_unref (self);
+
   gdk_threads_leave ();
 }
 
 static void
 ensure_online_button (GtkAppChooserDialog *self)
 {
-  _gtk_app_chooser_online_get_default_async (app_chooser_online_get_default_ready_cb, self);
+  _gtk_app_chooser_online_get_default_async (app_chooser_online_get_default_ready_cb,
+                                             g_object_ref (self));
 }
 
 /* An application is valid if:
@@ -298,6 +308,9 @@ gtk_app_chooser_dialog_response (GtkDialog *dialog,
     case GTK_RESPONSE_OK:
       add_or_find_application (self);
       break;
+    case GTK_RESPONSE_CANCEL:
+    case GTK_RESPONSE_DELETE_EVENT:
+      self->priv->dismissed = TRUE;
     default :
       break;
     }