diff --git a/mongoengine/base.py b/mongoengine/base.py
index 82f79d3b2..dc7ef8a08 100644
--- a/mongoengine/base.py
+++ b/mongoengine/base.py
@@ -11,7 +11,7 @@
 from queryset import DO_NOTHING
 
 from mongoengine import signals
-from mongoengine.python_support import (PY3, PY25, txt_type,
+from mongoengine.python_support import (PY3, UNICODE_KWARGS, txt_type,
                                         to_str_keys_recursive)
 
 import pymongo
@@ -1054,9 +1054,9 @@ def _from_son(cls, son):
         # class if unavailable
         class_name = son.get('_cls', cls._class_name)
         data = dict(("%s" % key, value) for key, value in son.items())
-        if PY25:
-            # PY25 cannot handle unicode keys passed to class constructor
-            # example: cls(**data)
+        if not UNICODE_KWARGS:
+            # python 2.6.4 and lower cannot handle unicode keys
+            # passed to class constructor example: cls(**data)
             to_str_keys_recursive(data)
 
         if '_types' in data:
diff --git a/mongoengine/python_support.py b/mongoengine/python_support.py
index 02dc28619..097740eb1 100644
--- a/mongoengine/python_support.py
+++ b/mongoengine/python_support.py
@@ -4,6 +4,7 @@
 
 PY3 = sys.version_info[0] == 3
 PY25 = sys.version_info[:2] == (2, 5)
+UNICODE_KWARGS = int(''.join([str(x) for x in sys.version_info[:3]])) > 264
 
 if PY3:
     import codecs