diff --git a/ponsim/bal_servicer.py b/ponsim/bal_servicer.py
index f036d67..1b7c4d4 100644
--- a/ponsim/bal_servicer.py
+++ b/ponsim/bal_servicer.py
@@ -18,7 +18,8 @@
 from voltha.protos import third_party
 from voltha.protos.ponsim_pb2 import PonSimDeviceInfo
 from google.protobuf.empty_pb2 import Empty
-from voltha.adapters.asfvolt16_olt.protos.bal_pb2 import BalServicer, BalErr
+from voltha.adapters.asfvolt16_olt.protos.bal_pb2_grpc import BalServicer
+from voltha.adapters.asfvolt16_olt.protos.bal_pb2 BalErr
 from voltha.adapters.asfvolt16_olt.protos.bal_errno_pb2 import BAL_ERR_OK
 
 _ = third_party
diff --git a/ponsim/grpc_server.py b/ponsim/grpc_server.py
index 9165433..3185c9e 100644
--- a/ponsim/grpc_server.py
+++ b/ponsim/grpc_server.py
@@ -19,9 +19,9 @@
 from concurrent import futures
 
 from voltha.protos import third_party
-from voltha.protos.ponsim_pb2 import add_PonSimServicer_to_server
-from voltha.protos.ponsim_pb2 import add_XPonSimServicer_to_server
-from voltha.adapters.asfvolt16_olt.protos.bal_pb2 import add_BalServicer_to_server
+from voltha.protos.ponsim_pb2_grpc import add_PonSimServicer_to_server
+from voltha.protos.ponsim_pb2_grpc import add_XPonSimServicer_to_server
+from voltha.adapters.asfvolt16_olt.protos.bal_pb2_grpc import add_BalServicer_to_server
 from ponsim_servicer import FlowUpdateHandler, XPonHandler
 from bal_servicer import BalHandler
 
diff --git a/ponsim/ponsim_servicer.py b/ponsim/ponsim_servicer.py
index ccfec38..6c3243d 100644
--- a/ponsim/ponsim_servicer.py
+++ b/ponsim/ponsim_servicer.py
@@ -16,9 +16,9 @@
 import structlog
 from common.utils.grpc_utils import twisted_async
 from voltha.protos import third_party
-from voltha.protos.ponsim_pb2 import PonSimServicer, PonSimDeviceInfo
+from voltha.protos.ponsim_pb2_grpc import PonSimServicer, XPonSimServicer
+from voltha.protos.ponsim_pb2 import PonSimDeviceInfo
 from google.protobuf.empty_pb2 import Empty
-from voltha.protos.ponsim_pb2 import XPonSimServicer
 
 _ = third_party