diff --git a/src/maestral_cocoa/dialogs.py b/src/maestral_cocoa/dialogs.py
index f85e584a..a0d6a89b 100644
--- a/src/maestral_cocoa/dialogs.py
+++ b/src/maestral_cocoa/dialogs.py
@@ -176,7 +176,7 @@ def __init__(
         app: toga.App | None = None,
     ) -> None:
         self.progress_bar = toga.ProgressBar(
-            max=0,
+            max=None,
             style=Pack(
                 width=self.CONTENT_WIDTH,
                 padding=(0, 0, 10, 0),