diff --git a/shell/panelshadows.cpp b/shell/panelshadows.cpp
--- a/shell/panelshadows.cpp
+++ b/shell/panelshadows.cpp
@@ -175,6 +175,7 @@
         return;
     }
 
+    d->m_windows[window] = enabledBorders;
     d->updateShadow(window, enabledBorders);
 }