diff --git a/daemon/core/api/tlv/coreapi.py b/daemon/core/api/tlv/coreapi.py
index 73cb0daf..627e6714 100644
--- a/daemon/core/api/tlv/coreapi.py
+++ b/daemon/core/api/tlv/coreapi.py
@@ -748,13 +748,11 @@ class CoreMessage(object):
         :return: packed data
         :rtype: str
         """
-        tlv_data = ""
         keys = sorted(self.tlv_data.keys())
-
+        tlv_data = b""
         for key in keys:
             value = self.tlv_data[key]
             tlv_data += self.tlv_class.pack(key, value)
-
         return tlv_data
 
     def repack(self):
diff --git a/daemon/core/plugins/sdt.py b/daemon/core/plugins/sdt.py
index 0cd200ba..79d7597c 100644
--- a/daemon/core/plugins/sdt.py
+++ b/daemon/core/plugins/sdt.py
@@ -4,14 +4,9 @@ sdt.py: Scripted Display Tool (SDT3D) helper
 
 import logging
 import socket
-
-from future.standard_library import install_aliases
-install_aliases()
-
-from urllib.parse import urlparse
+from future.moves.urllib.parse import urlparse
 
 from core import constants
-from core.nodes.base import NodeBase, CoreNetworkBase
 from core.emulator.enumerations import EventTypes
 from core.emulator.enumerations import LinkTlvs
 from core.emulator.enumerations import LinkTypes
@@ -20,6 +15,7 @@ from core.emulator.enumerations import MessageTypes
 from core.emulator.enumerations import NodeTlvs
 from core.emulator.enumerations import NodeTypes
 from core.nodes import nodeutils
+from core.nodes.base import NodeBase, CoreNetworkBase
 
 
 # TODO: A named tuple may be more appropriate, than abusing a class dict like this