diff --git a/voltha/adapters/ponsim_olt/ponsim_olt.py b/voltha/adapters/ponsim_olt/ponsim_olt.py
index 01f008e..dcc55a7 100644
--- a/voltha/adapters/ponsim_olt/ponsim_olt.py
+++ b/voltha/adapters/ponsim_olt/ponsim_olt.py
@@ -158,7 +158,7 @@
 
     def __del__(self):
         if self.io_port is not None:
-            registry('frameio').del_interface(self.interface)
+            registry('frameio').close_port(self.io_port)
 
     def get_channel(self):
         if self.channel is None:
@@ -266,7 +266,7 @@
 
         # finally, open the frameio port to receive in-band packet_in messages
         self.log.info('registering-frameio')
-        self.io_port = registry('frameio').add_interface(
+        self.io_port = registry('frameio').open_port(
             self.interface, self.rcv_io, is_inband_frame)
         self.log.info('registered-frameio')