--- a/src/hgext3rd/hggit_serve/_export.py	Thu Feb 19 01:13:56 2026 -0500
+++ b/src/hgext3rd/hggit_serve/_export.py	Fri Feb 20 21:05:31 2026 -0500
@@ -151,15 +151,25 @@
 # Hooks
 #
 
+_AX_ALWAYS = b'always'
+_AX_DEFAULT = b'default'
+_AX_NEVER = b'never'
+
 
 def _export_hook(ui: hgui.ui, repo: hgrepo.IRepo, **__: object) -> None:
     """Maybe exports the repository to get after we get new revs."""
     if not is_gitty(repo):
         return
     auto_export = ui.config(b'hggit-serve', b'auto-export')
-    if auto_export == b'never':
+    if auto_export == _AX_NEVER:
         return
-    if auto_export == b'always' or git_handler.has_gitrepo(repo):
+    if auto_export == _AX_ALWAYS or git_handler.has_gitrepo(repo):
+        if auto_export not in (None, _AX_ALWAYS, _AX_DEFAULT):
+            ui.warn(
+                b'unrecognized auto-export setting %s; using %s',
+                auto_export,
+                _AX_DEFAULT,
+            )
         if _is_importing(repo):
             ui.note(b'currently importing revs from git; not exporting\n')
             return