diff --git a/application/source/data/transformer.mjs b/application/source/data/transformer.mjs
index 45945146bbd4e6537f00f877c30776be0a8ad670..4e9fe3fe868254c6ada300534119c0ee260901a7 100644
--- a/application/source/data/transformer.mjs
+++ b/application/source/data/transformer.mjs
@@ -406,8 +406,9 @@ function transform(value) {
                     throw new Error("missing key parameter");
                 }
                 
+                // add empty strings
                 if (isString(key)&&key.trim()==="") {
-                    concat += key;
+                    concat += key; 
                     continue;
                 }