--- a/plugins/mod_storage_sql.lua	Mon Nov 28 07:30:21 2016 +0100
+++ b/plugins/mod_storage_sql.lua	Mon Nov 28 07:30:39 2016 +0100
@@ -7,10 +7,8 @@
 local uuid = require "util.uuid";
 local resolve_relative_path = require "util.paths".resolve_relative_path;
 
-local stanza_mt = require"util.stanza".stanza_mt;
-local getmetatable = getmetatable;
+local is_stanza = require"util.stanza".is_stanza;
 local t_concat = table.concat;
-local function is_stanza(x) return getmetatable(x) == stanza_mt; end
 
 local noop = function() end
 local unpack = unpack