diff --git a/koji/util.py b/koji/util.py
index ba999a7d..cbf75b8f 100644
--- a/koji/util.py
+++ b/koji/util.py
@@ -21,6 +21,7 @@
 from __future__ import absolute_import
 import calendar
 import datetime
+from koji.xmlrpcplus import DateTime
 from fnmatch import fnmatch
 import koji
 import logging
@@ -186,6 +187,8 @@ def encode_datetime(value):
     """Convert datetime objects to strings"""
     if isinstance(value, datetime.datetime):
         return value.isoformat(' ')
+    elif isinstance(value, DateTime):
+        return datetime.datetime(*value.timetuple()[:6]).isoformat(' ')
     else:
         return value
 
diff --git a/koji/xmlrpcplus.py b/koji/xmlrpcplus.py
index 6a736f49..9164cd77 100644
--- a/koji/xmlrpcplus.py
+++ b/koji/xmlrpcplus.py
@@ -11,6 +11,7 @@ import types
 getparser = xmlrpc_client.getparser
 loads = xmlrpc_client.loads
 Fault = xmlrpc_client.Fault
+DateTime = xmlrpc_client.DateTime
 
 
 class ExtendedMarshaller(xmlrpc_client.Marshaller):
diff --git a/tests/test_lib/test_encode_datetime.py b/tests/test_lib/test_encode_datetime.py
index 7617c264..1583c374 100644
--- a/tests/test_lib/test_encode_datetime.py
+++ b/tests/test_lib/test_encode_datetime.py
@@ -2,6 +2,7 @@ import datetime
 import unittest
 
 import koji.util
+from koji.xmlrpcplus import DateTime
 
 
 class testEncodeDatetime(unittest.TestCase):
@@ -22,6 +23,15 @@ class testEncodeDatetime(unittest.TestCase):
             self.assertEqual(chk1, dstr)
             self.assertEqual(chk2, dstr)
 
+    def test_xmlrpc_dates(self):
+        # we skip the last because xmlrpc's DateTime class does not preserve
+        # fractions of seconds
+        for dt, dstr in self.DATES[:2]:
+            dt = DateTime(dt)
+            chk1 = koji.util.encode_datetime(dt)
+            chk2 = koji.util.encode_datetime_recurse(dt)
+            self.assertEqual(chk1, dstr)
+            self.assertEqual(chk2, dstr)
 
     def test_embedded_dates(self):
         dt1, ds1 = self.DATES[0]