diff --git a/components/rtgui/common/region.c b/components/rtgui/common/region.c
index bcb8bacb2e1d8b7fd4dc473352b67e6b8e284ef9..d5a849c4dcc1595d8032e606e92e9d8f42a36ccf 100644
--- a/components/rtgui/common/region.c
+++ b/components/rtgui/common/region.c
@@ -175,7 +175,7 @@ void rtgui_region_init_rect(rtgui_region_t *region,
 	region->data = RT_NULL;
 }
 
-void rtgui_region_init_with_extents(rtgui_region_t *region, rtgui_rect_t *extents)
+void rtgui_region_init_with_extents(rtgui_region_t *region, const rtgui_rect_t *extents)
 {
 	region->extents = *extents;
 	region->data = RT_NULL;
diff --git a/components/rtgui/include/rtgui/region.h b/components/rtgui/include/rtgui/region.h
index 5a2362892c35617b1f5a56b12e66b8f50b35e2b2..3b292f735000ea619b387c6e9197cae8b7905627 100644
--- a/components/rtgui/include/rtgui/region.h
+++ b/components/rtgui/include/rtgui/region.h
@@ -47,7 +47,7 @@ typedef enum
 void rtgui_region_init(rtgui_region_t *region);
 void rtgui_region_init_rect(rtgui_region_t *region,
 	int x, int y, unsigned int width, unsigned int height);
-void rtgui_region_init_with_extents(rtgui_region_t *region, rtgui_rect_t *extents);
+void rtgui_region_init_with_extents(rtgui_region_t *region, const rtgui_rect_t *extents);
 void rtgui_region_fini (rtgui_region_t *region);
 
 void rtgui_region_translate (rtgui_region_t *region, int x, int y);