diff --git a/li.strolch.service/src/main/java/li/strolch/service/JsonServiceArgument.java b/li.strolch.service/src/main/java/li/strolch/service/JsonServiceArgument.java
index 802ef8936..0bb1bbc4e 100644
--- a/li.strolch.service/src/main/java/li/strolch/service/JsonServiceArgument.java
+++ b/li.strolch.service/src/main/java/li/strolch/service/JsonServiceArgument.java
@@ -11,6 +11,12 @@ import li.strolch.service.api.ServiceArgument;
  * @author Robert von Burg <eitch@eitchnet.ch>
  */
 public class JsonServiceArgument extends ServiceArgument {
+
+	/**
+	 * the objectType - its context is defined by the service
+	 */
+	public String objectType;
+
 	/**
 	 * the objectId - its context is defined by the service
 	 */