diff --git a/demos/blockfactory/factory_utils.js b/demos/blockfactory/factory_utils.js
index 048760567..dfed4578e 100644
--- a/demos/blockfactory/factory_utils.js
+++ b/demos/blockfactory/factory_utils.js
@@ -490,7 +490,7 @@ FactoryUtils.getFieldsJs_ = function(block) {
           var width = Number(block.getFieldValue('WIDTH'));
           var height = Number(block.getFieldValue('HEIGHT'));
           var alt = JSON.stringify(block.getFieldValue('ALT'));
-          var flipRtl = Json.stringify(block.getFieldValue('FLIP_RTL'));
+          var flipRtl = JSON.stringify(block.getFieldValue('FLIP_RTL'));
           fields.push('new Blockly.FieldImage(' +
               src + ', ' + width + ', ' + height +
               ', { alt: ' + alt + ', flipRtl: ' + flipRtl + ' })');