diff --git a/src/main/java/nl/tno/oorti/impl/OORTIambassadorImpl.java b/src/main/java/nl/tno/oorti/impl/OORTIambassadorImpl.java
index d7c413f..9fcac99 100644
--- a/src/main/java/nl/tno/oorti/impl/OORTIambassadorImpl.java
+++ b/src/main/java/nl/tno/oorti/impl/OORTIambassadorImpl.java
@@ -1335,10 +1335,14 @@ public boolean isAttributeOwnedByFederate(Object theObject, OOattribute theAttri
   @Override
   public String getObjectClassName(Class theClass)
       throws ObjectClassNotDefined, FederateNotExecutionMember, NotConnected, RTIinternalError {
-    
+
     ExecutionContext ec = ecm.getExecutionContextIfExists();
 
-    return ec.getOcm().getObjectClassIfExists(theClass).getName();
+    try {
+      return ec.getOcm().create(theClass).getName();
+    } catch (AttributeNotDefined ex) {
+      throw new ObjectClassNotDefined(ex.getMessage(), ex);
+    }
   }
 
   @Override
@@ -1359,7 +1363,11 @@ public String getInteractionClassName(Class theClass)
 
     ExecutionContext ec = ecm.getExecutionContextIfExists();
 
-    return ec.getIcm().getInteractionClassIfExists(theClass).getName();
+    try {
+      return ec.getIcm().create(theClass).getName();
+    } catch (InteractionParameterNotDefined ex) {
+      throw new InteractionClassNotDefined(ex.getMessage(), ex);
+    }
   }
 
   @Override