diff --git a/extra/pydes/pyDes.py b/extra/pydes/pyDes.py
index 110e4fc8d..e19297f9c 100644
--- a/extra/pydes/pyDes.py
+++ b/extra/pydes/pyDes.py
@@ -230,7 +230,7 @@ class _baseDes(object):
 		# there is no way to correctly decode the data into bytes.
 		if _pythonMajorVersion < 3:
 			if isinstance(data, unicode):
-				data = str(data)
+				data = data.encode('utf8')
 		else:
 			if isinstance(data, str):
 				# Only accept ascii unicode values.