diff --git a/xos/synchronizer/steps/sync_port_addresses.py b/xos/synchronizer/steps/sync_port_addresses.py
index 37d8dc6..b3a7837 100644
--- a/xos/synchronizer/steps/sync_port_addresses.py
+++ b/xos/synchronizer/steps/sync_port_addresses.py
@@ -39,6 +39,8 @@
         if vtn_service.vtnAPIVersion >= 2:
             logger.info("skipping SyncPortAddresses due to VTN API Version")
             return
+        else:
+            raise Exception("VTN API Version 1 is no longer supported by VTN Synchronizer")
 
         # build up a dictionary of port-->[wan_addrs] mappings
         port_addrs = {}
diff --git a/xos/synchronizer/steps/sync_vtn_service.py b/xos/synchronizer/steps/sync_vtn_service.py
index 112fc5a..97f0db6 100644
--- a/xos/synchronizer/steps/sync_vtn_service.py
+++ b/xos/synchronizer/steps/sync_vtn_service.py
@@ -221,6 +221,7 @@
         else:
             # default to legacy
             logger.info("Using Old API")
-            self.sync_legacy_vtn_api()
+            raise Exception("VTN API Version 1 is no longer supported by VTN Synchronizer")
+            #self.sync_legacy_vtn_api()