diff --git a/include/ui/Region.h b/include/ui/Region.h
index 49740f7..2a14918 100644
--- a/include/ui/Region.h
+++ b/include/ui/Region.h
@@ -35,6 +35,8 @@
 class Region : public LightFlattenable<Region>
 {
 public:
+    static const Region INVALID_REGION;
+
                         Region();
                         Region(const Region& rhs);
     explicit            Region(const Rect& rhs);