diff --git a/src/NewTools-MethodBrowsers/StMessageBrowser.class.st b/src/NewTools-MethodBrowsers/StMessageBrowser.class.st
index 4d95ce76..f24c2fc0 100644
--- a/src/NewTools-MethodBrowsers/StMessageBrowser.class.st
+++ b/src/NewTools-MethodBrowsers/StMessageBrowser.class.st
@@ -625,6 +625,7 @@ StMessageBrowser >> windowIsClosing [
 
 { #category : 'private' }
 StMessageBrowser >> windowTitle [
-
-	^ (title ifNil: [ 'Message Browser' ]), ' [' , messageList numberOfElements printString , ']'
+	| msg |
+	msg := messageList ifNil: [ '' ] ifNotNil: [ ' [' , messageList numberOfElements printString , ']' ].
+	^ (title ifNil: [ 'Message Browser' ]), msg 
 ]
diff --git a/src/NewTools-MethodBrowsers/StMessageBrowserTest.class.st b/src/NewTools-MethodBrowsers/StMessageBrowserTest.class.st
new file mode 100644
index 00000000..ee234f39
--- /dev/null
+++ b/src/NewTools-MethodBrowsers/StMessageBrowserTest.class.st
@@ -0,0 +1,21 @@
+Class {
+	#name : 'StMessageBrowserTest',
+	#superclass : 'TestCase',
+	#classVars : [
+		'UsingLayout'
+	],
+	#category : 'NewTools-MethodBrowsers-Senders',
+	#package : 'NewTools-MethodBrowsers',
+	#tag : 'Senders'
+}
+
+{ #category : 'tests' }
+StMessageBrowserTest >> testOpenWithoutMessageShouldNotDNU [
+
+	| br |
+	[ br := StMessageBrowser new.
+	self shouldnt: [ br open ] raise: MessageNotUnderstood.
+	] ensure: [ br window close ]
+
+	
+]