diff --git a/libretranslate/app.py b/libretranslate/app.py
index 4706abd..21f9095 100644
--- a/libretranslate/app.py
+++ b/libretranslate/app.py
@@ -243,7 +243,7 @@ def create_app(args):
                 elif (
                     args.require_api_key_origin
                     and api_keys_db.lookup(ak) is None
-                    and not re.match(args.require_api_key_origin, request.headers.get("Origin"))
+                    and not re.match(args.require_api_key_origin, request.headers.get("Origin", ""))
                 ):
                     description = _("Please contact the server operator to get an API key")
                     if args.get_api_key_link: