diff --git a/mariadb/mariadb_connection.c b/mariadb/mariadb_connection.c
index db210d8..438ee3f 100644
--- a/mariadb/mariadb_connection.c
+++ b/mariadb/mariadb_connection.c
@@ -319,7 +319,7 @@ MrdbConnection_Initialize(MrdbConnection *self,
     PyObject *converter= NULL;
 
     if (!PyArg_ParseTupleAndKeywords(args, dsnargs,
-                "|sssssisiiibbssssssssssibisibssssOO:connect",
+                "|zzzzziziiibbzzzzzzzzzzibizibzzzzOO:connect",
                 dsn_keys,
                 &dsn, &host, &user, &password, &schema, &port, &socket,
                 &connect_timeout, &read_timeout, &write_timeout,