diff --git a/reactos/include/defines.h b/reactos/include/defines.h
index c04246ece6b..d768b220f26 100644
--- a/reactos/include/defines.h
+++ b/reactos/include/defines.h
@@ -1297,6 +1297,16 @@ extern "C" {
 #define DCX_VALIDATE	(0x200000L)
 #define DCX_USESTYLE         (0x00010000L)
 #define DCX_NORECOMPUTE      (0x00100000L)
+#define DCX_EXCLUDEUPDATE    (0x00000100L)
+#define DCX_INTERSECTUPDATE  (0x00000200L)
+
+/* Internal DCX flags */
+#define DCX_DCEEMPTY		(0x00000800L)
+#define DCX_DCEBUSY		(0x00001000L)
+#define DCX_DCEDIRTY		(0x00002000L)
+#define DCX_WINDOWPAINT		(0x00020000L)
+#define DCX_KEEPCLIPRGN		(0x00040000L)
+#define DCX_NOCLIPCHILDREN      (0x00080000L)
 
 /* GetDeviceCaps */
 #define DRIVERVERSION	(0)