diff --git a/src/NewTools-MethodBrowsers/StMethodBrowser.class.st b/src/NewTools-MethodBrowsers/StMethodBrowser.class.st
index 5f1399178..d547a069a 100644
--- a/src/NewTools-MethodBrowsers/StMethodBrowser.class.st
+++ b/src/NewTools-MethodBrowsers/StMethodBrowser.class.st
@@ -592,8 +592,11 @@ StMethodBrowser >> initializePresenters [
 StMethodBrowser >> initializeWindow: aWindowPresenter [
 
 	super initializeWindow: aWindowPresenter.
-	aWindowPresenter whenClosedDo: [ TestCase historyAnnouncer unsubscribe: methodList ].
-
+	aWindowPresenter whenWillCloseDo: [ :ann |
+			textPresenter isDirty ifTrue: [
+					(self application confirm: 'Changes have not been saved.
+Is it OK to discard changes?') ifFalse: [ ann denyClose ] ] ].
+	aWindowPresenter whenClosedDo: [ TestCase historyAnnouncer unsubscribe: methodList ]
 ]
 
 { #category : 'private' }