diff --git a/src/opensesim/world/Exchange.java b/src/opensesim/world/Exchange.java
index 3d833ae..2feacef 100644
--- a/src/opensesim/world/Exchange.java
+++ b/src/opensesim/world/Exchange.java
@@ -37,7 +37,7 @@ import org.json.JSONObject;
  */
 public class Exchange implements Configurable, GetJson {
 
-    private GodWorld world;
+    protected GodWorld world;
     private String name;
     private String symbol;