diff --git a/CHANGELOG.TXT b/CHANGELOG.TXT
index 60f02b166..2239cadd2 100644
--- a/CHANGELOG.TXT
+++ b/CHANGELOG.TXT
@@ -16,6 +16,7 @@
   Fix issue MR-99 - Integrate Spanish translation
   Fix issue MR-101 - Collapse all folders causes a NullReferenceException
   Fix issue MR-131 - RD Gateway does not respect setting for use different credentials
+  Fix issue MR-165 - Can't close About window if it is the last tab
   Fix issue MR-166 - Inheritance button is disabled on some connections
   Fix issue MR-172 - RDGatewayPassword is unencrypted in confCons.xml file
   Fix issue MR-176 - Del key while editing connection name triggers 'Delete Connection'
diff --git a/mRemoteV1/UI/UI.Window.Base.vb b/mRemoteV1/UI/UI.Window.Base.vb
index 1bd336442..7461c00c3 100644
--- a/mRemoteV1/UI/UI.Window.Base.vb
+++ b/mRemoteV1/UI/UI.Window.Base.vb
@@ -34,6 +34,30 @@ Namespace UI
             End Sub
 #End Region
 
+#Region "Private Methods"
+            Private Sub Base_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
+                If TypeOf Me Is Connection Then
+                    frmMain.pnlDock.DocumentStyle = DocumentStyle.DockingSdi
+                Else
+                    frmMain.pnlDock.DocumentStyle = DocumentStyle.DockingWindow
+                End If
+            End Sub
+
+            Private Sub Base_FormClosed(sender As System.Object, e As System.Windows.Forms.FormClosedEventArgs) Handles MyBase.FormClosed
+                Dim nonConnectionPanelCount As Integer = 0
+                For Each document As DockContent In frmMain.pnlDock.Documents
+                    If document IsNot Me And Not TypeOf document Is Connection Then
+                        nonConnectionPanelCount = nonConnectionPanelCount + 1
+                    End If
+                Next
+
+                If nonConnectionPanelCount = 0 Then
+                    frmMain.pnlDock.DocumentStyle = DocumentStyle.DockingSdi
+                Else
+                    frmMain.pnlDock.DocumentStyle = DocumentStyle.DockingWindow
+                End If
+            End Sub
+#End Region
         End Class
     End Namespace
 End Namespace
\ No newline at end of file