diff --git a/frontends/atari/gui.c b/frontends/atari/gui.c
index 1287b4715..ad568b761 100644
--- a/frontends/atari/gui.c
+++ b/frontends/atari/gui.c
@@ -385,34 +385,41 @@ static void atari_window_reformat(struct gui_window *gw)
     }
 }
 
-static void gui_window_redraw_window(struct gui_window *gw)
-{
-	//CMP_BROWSER b;
-	GRECT rect;
-	if (gw == NULL)
-		return;
-	//b = gw->browser;
-	window_get_grect(gw->root, BROWSER_AREA_CONTENT, &rect);
-	window_schedule_redraw_grect(gw->root, &rect);
-}
 
-static void gui_window_update_box(struct gui_window *gw, const struct rect *rect)
+/**
+ * Invalidates an area of an atari browser window
+ *
+ * \param gw gui_window
+ * \param rect area to redraw or NULL for the entire window area
+ * \return NSERROR_OK on success or appropriate error code
+ */
+static nserror
+atari_window_invalidate_area(struct gui_window *gw,
+			     const struct rect *rect)
 {
     GRECT area;
-    struct gemtk_wm_scroll_info_s *slid;
 
-    if (gw == NULL)
-	return;
-
-    slid = gemtk_wm_get_scroll_info(gw->root->win);
+    if (gw == NULL) {
+	return NSERROR_BAD_PARAMETER;
+    }
 
     window_get_grect(gw->root, BROWSER_AREA_CONTENT, &area);
-    area.g_x += rect->x0 - (slid->x_pos * slid->x_unit_px);
-    area.g_y += rect->y0 - (slid->y_pos * slid->y_unit_px);
-    area.g_w = rect->x1 - rect->x0;
-    area.g_h = rect->y1 - rect->y0;
+
+    if (rect != NULL) {
+	    struct gemtk_wm_scroll_info_s *slid;
+
+	    slid = gemtk_wm_get_scroll_info(gw->root->win);
+
+	    area.g_x += rect->x0 - (slid->x_pos * slid->x_unit_px);
+	    area.g_y += rect->y0 - (slid->y_pos * slid->y_unit_px);
+	    area.g_w = rect->x1 - rect->x0;
+	    area.g_h = rect->y1 - rect->y0;
+    }
+
     //dbg_grect("update box", &area);
     window_schedule_redraw_grect(gw->root, &area);
+
+    return NSERROR_OK;
 }
 
 bool gui_window_get_scroll(struct gui_window *w, int *sx, int *sy)
@@ -680,7 +687,7 @@ static void gui_window_new_content(struct gui_window *w)
     slid->x_pos = 0;
     slid->y_pos = 0;
     gemtk_wm_update_slider(w->root->win, GEMTK_WM_VH_SLIDER);
-    gui_window_redraw_window(w);
+    atari_window_invalidate_area(w, NULL);
 }
 
 
@@ -1051,8 +1058,7 @@ static void gui_init(int argc, char** argv)
 static struct gui_window_table atari_window_table = {
     .create = gui_window_create,
     .destroy = gui_window_destroy,
-    .redraw = gui_window_redraw_window,
-    .update = gui_window_update_box,
+    .invalidate = atari_window_invalidate_area,
     .get_scroll = gui_window_get_scroll,
     .set_scroll = gui_window_set_scroll,
     .get_dimensions = gui_window_get_dimensions,