diff --git a/scripts/production_locales b/scripts/production_locales
index a4ff3a1f64cfe45a3db14b8063cf877263b8767e..7245ecbfea8ce0ae0f4ba1698ccf3c75734783d3 100755
--- a/scripts/production_locales
+++ b/scripts/production_locales
@@ -7,7 +7,7 @@ var path = require('path');
 process.env['VAR_PATH'] = '/tmp/browserid';
 
 // Pick up production languages
-process.env['CONFIG_FILES'] = path.join(__dirname, '..', 'config', 'local.json');
+process.env['CONFIG_FILES'] = process.env['CONFIG_FILES'] || path.join(__dirname, '..', 'config', 'local.json');
 
 var path = require('path'),
     format = require('util').format,