diff --git a/System/Libraries/Gui.HC b/System/Libraries/Gui.HC
index 1c2f34c..0c8c68f 100644
--- a/System/Libraries/Gui.HC
+++ b/System/Libraries/Gui.HC
@@ -124,6 +124,7 @@ class Window {
     Bool alpha;
     Bool refresh;
     Bool repainting;
+    Bool explicit_repaint;
     CTask* client;
     I64 x;
     I64 y;