diff --git a/pysnmp/entity/rfc3413/ntforg.py b/pysnmp/entity/rfc3413/ntforg.py
index <HASH>..<HASH> 100644
--- a/pysnmp/entity/rfc3413/ntforg.py
+++ b/pysnmp/entity/rfc3413/ntforg.py
@@ -1,4 +1,8 @@
 import time
+try:
+    from sys import version_info
+except ImportError:
+    version_info = ( 0, 0 )   # a really early version
 from pysnmp.entity.rfc3413 import config
 from pysnmp.proto.proxy import rfc2576
 from pysnmp.proto.api import v2c
@@ -160,6 +164,8 @@ class NotificationOriginator:
                 varBinds.append((mibNode.name + (0,), mibNode.syntax))
 
             if additionalVarBinds:
+                if version_info < (1, 6):
+                    additionalVarBinds = list(additionalVarBinds)
                 varBinds.extend(additionalVarBinds)
 
             for varName, varVal in varBinds:
python<I> compatibility fix: [].extend() expects a list, not tuple