--- a/mod_http_oauth2/mod_http_oauth2.lua	Sun Dec 03 23:44:18 2023 +0100
+++ b/mod_http_oauth2/mod_http_oauth2.lua	Sun Dec 03 23:51:54 2023 +0100
@@ -1333,6 +1333,9 @@
 
 local function redirect_uri_allowed(redirect_uri, client_uri, app_type)
 	local uri = url.parse(redirect_uri);
+	if not uri then
+		return false;
+	end
 	if not uri.scheme then
 		return false; -- no relative URLs
 	end