diff --git a/src/winforms/toga_winforms/factory.py b/src/winforms/toga_winforms/factory.py
index 29becaa6ca..f223f53a46 100644
--- a/src/winforms/toga_winforms/factory.py
+++ b/src/winforms/toga_winforms/factory.py
@@ -20,6 +20,7 @@
 from .widgets.splitcontainer import *
 from .widgets.switch import *
 from .widgets.table import *
+from .widgets.tree import *
 from .widgets.webview import *
 from .window import Window