diff --git a/li.strolch.model/src/main/java/li/strolch/model/json/StrolchElementToJsonVisitor.java b/li.strolch.model/src/main/java/li/strolch/model/json/StrolchElementToJsonVisitor.java
index b33f7c58a..a4b1f29ec 100644
--- a/li.strolch.model/src/main/java/li/strolch/model/json/StrolchElementToJsonVisitor.java
+++ b/li.strolch.model/src/main/java/li/strolch/model/json/StrolchElementToJsonVisitor.java
@@ -633,7 +633,7 @@ public class StrolchElementToJsonVisitor implements StrolchElementVisitor<JsonEl
 
 			if (rootJ.has(paramId)) {
 				throw new StrolchModelException(
-						"JsonObject already has a member with ID " + paramId + ": " + parameterBag.getLocator());
+						"JsonObject already has a member with ID " + paramId + ": " + param.getLocator());
 			}
 
 			StrolchValueType type = StrolchValueType.parse(param.getType());