diff --git a/XMonad/Layout/Hidden.hs b/XMonad/Layout/Hidden.hs
index e171e098..b5e6999b 100644
--- a/XMonad/Layout/Hidden.hs
+++ b/XMonad/Layout/Hidden.hs
@@ -110,7 +110,7 @@ popNewestHiddenWindow = sendMessage PopNewestHiddenWindow
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 hideWindowMsg :: HiddenWindows a -> Window -> X (Maybe (HiddenWindows a))
 hideWindowMsg (HiddenWindows hidden) win = do
-  windows (W.delete' win)
+  modify (\s -> s { windowset = W.delete' win $ windowset s })
   return . Just . HiddenWindows $ hidden ++ [win]
 
 --------------------------------------------------------------------------------
@@ -130,4 +130,5 @@ popOldestMsg (HiddenWindows (win:rest)) = do
 
 --------------------------------------------------------------------------------
 restoreWindow :: Window -> X ()
-restoreWindow = windows . W.insertUp
+restoreWindow win =
+  modify (\s -> s { windowset = W.insertUp win $ windowset s })