diff --git a/AppKit/CPWindow/CPWindow.j b/AppKit/CPWindow/CPWindow.j
index 90917f81e..53c567bb3 100644
--- a/AppKit/CPWindow/CPWindow.j
+++ b/AppKit/CPWindow/CPWindow.j
@@ -2390,7 +2390,7 @@ CPTexturedBackgroundWindowMask
 /*!
     Returns YES if the window is minimized.
 */
-- (void)isMiniaturized
+- (BOOL)isMiniaturized
 {
     return _isMiniaturized;
 }