diff --git a/aclpc/acl-class.lisp b/aclpc/acl-class.lisp
index fb942663ba7a8c537698d2f46a30f9cb47aa1b75..3f3ca0a3c1a107d158b4c2433144aa7eec269da8 100644
--- a/aclpc/acl-class.lisp
+++ b/aclpc/acl-class.lisp
@@ -481,18 +481,6 @@
       (setf (minimized-p sheet) (= wparam win::SIZE_MINIMIZED)))
     (win-result *acl-port*)))
 
-(defmethod silica::sheet-flags ((sheet acl-top-level-sheet))
-  `(,@(when (maximized-p sheet) (list :maximized))
-      ,@(when (minimized-p sheet) (list :minimized))))
-
-(defmethod (setf silica::sheet-flags) (new-flags (sheet acl-top-level-sheet))
-  (let ((mirror (sheet-mirror sheet)))
-   (cond
-     ((member :maximized new-flags)
-      (win:ShowWindow mirror win:SW_MAXIMIZE))
-     ((member :minimized new-flags)
-      (win:ShowWindow mirror win:SW_MINIMIZE)))))
-
 ;; Process WM_GETMINMAXINFO
 (defun ongetminmaxinfo (window msg wparam lparam)
   (let ((sheet (mirror->sheet *acl-port* window)))
diff --git a/aclpc/acl-mirror.lisp b/aclpc/acl-mirror.lisp
index bb7993b271582643074eb9582b3a1f6ded43cd78..d41798c75eb4b5d5b96e9539f122f6468d26293f 100644
--- a/aclpc/acl-mirror.lisp
+++ b/aclpc/acl-mirror.lisp
@@ -525,3 +525,14 @@
 			(logior win:SWP_NOACTIVATE
 				win:SWP_NOZORDER)))))
 
+(defmethod silica::sheet-flags ((sheet acl-top-level-sheet))
+  `(,@(when (maximized-p sheet) (list :maximized))
+      ,@(when (minimized-p sheet) (list :minimized))))
+
+(defmethod (setf silica::sheet-flags) (new-flags (sheet acl-top-level-sheet))
+  (let ((mirror (sheet-mirror sheet)))
+   (cond
+     ((member :maximized new-flags)
+      (win:ShowWindow mirror win:SW_MAXIMIZE))
+     ((member :minimized new-flags)
+      (win:ShowWindow mirror win:SW_MINIMIZE)))))
\ No newline at end of file