diff --git a/scripts/renderer.js b/scripts/renderer.js
index 28e5079..9dbef15 100644
--- a/scripts/renderer.js
+++ b/scripts/renderer.js
@@ -15,7 +15,10 @@ function njkCompile(data) {
     return dictionary;
   });
   env.addFilter('json', dictionary => {
-    return JSON.stringify(dictionary || '');
+    if (typeof dictionary !== 'undefined' && dictionary !== null) {
+      return JSON.stringify(dictionary);
+    }
+    return '""';
   });
   return nunjucks.compile(data.text, env, data.path);
 }