diff --git a/widget/cocoa/nsCocoaWindow.mm b/widget/cocoa/nsCocoaWindow.mm
index f22aff445f0..cda84f24ed6 100644
--- a/widget/cocoa/nsCocoaWindow.mm
+++ b/widget/cocoa/nsCocoaWindow.mm
@@ -5737,11 +5737,11 @@ void nsCocoaWindow::HideWindowChrome(bool aShouldHide) {
 
   // Recreate the window with the right border style.
   NSRect frameRect = mWindow.frame;
-  BOOL restorable = mWindow.restorable;
+  BOOL isPrivateWindow = !mWindow.restorable;
   DestroyNativeWindow();
   nsresult rv = CreateNativeWindow(
       frameRect, aShouldHide ? BorderStyle::None : mBorderStyle, true,
-      restorable);
+      isPrivateWindow);
   NS_ENSURE_SUCCESS_VOID(rv);
 
   // Re-import state.