diff --git a/reactos/include/reactos/win32k/ntuser.h b/reactos/include/reactos/win32k/ntuser.h
index 1ee0d04f7f2..13900d4fb2a 100644
--- a/reactos/include/reactos/win32k/ntuser.h
+++ b/reactos/include/reactos/win32k/ntuser.h
@@ -1437,6 +1437,20 @@ NtUserRedrawWindow
  UINT flags
 );
 
+BOOL
+NTAPI
+NtUserInvalidateRect(
+    HWND hWnd,
+    CONST RECT *lpRect,
+    BOOL bErase);
+
+BOOL
+NTAPI
+NtUserInvalidateRgn(
+    HWND hWnd,
+    HRGN hRgn,
+    BOOL bErase);
+
 /* FIXME: These flag constans aren't what Windows uses. */
 #define REGISTERCLASS_ANSI	2
 #define REGISTERCLASS_SYSTEM	4