diff --git a/xpfe/appshell/src/nsAppShellService.cpp b/xpfe/appshell/src/nsAppShellService.cpp
index 24a1b6c1d356..dc6c21de837f 100644
--- a/xpfe/appshell/src/nsAppShellService.cpp
+++ b/xpfe/appshell/src/nsAppShellService.cpp
@@ -461,7 +461,7 @@ NS_IMETHODIMP nsAppShellService::Quit()
 	if ( mQuiting )
 		return NS_OK;
  nsresult rv;
- mQuiting = true;
+ mQuiting = PR_TRUE;
 	// now step through all opened registered windows and close them.
   NS_WITH_SERVICE(nsIWindowMediator, windowMediator, kWindowMediatorCID, &rv);
   if (NS_SUCCEEDED(rv)) {