diff --git a/distilclient/tests/unit/v2/test_invoices.py b/distilclient/tests/unit/v2/test_invoices.py
index eb3b30e..9ecd308 100644
--- a/distilclient/tests/unit/v2/test_invoices.py
+++ b/distilclient/tests/unit/v2/test_invoices.py
@@ -13,6 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import datetime
 import mock
 
 import distilclient
@@ -48,3 +49,13 @@ class InvoicesTest(utils.TestCase):
         mock_list.assert_called_with('/v2/invoices?start=2017-1-1'
                                      '&end=2018-2-1&detailed=False',
                                      'invoices')
+
+    @mock.patch.object(base.Manager, '_list')
+    def test_list_with_datetime(self, mock_list):
+        start = datetime.date(year=2017, day=1, month=1)
+        end = datetime.date(year=2018, day=1, month=2)
+        self.client.invoices.list(start, end,
+                                  'project_id')
+        mock_list.assert_called_with('/v2/invoices?start=2017-01-01'
+                                     '&end=2018-02-01&detailed=False'
+                                     '&project_id=project_id', 'invoices')
diff --git a/distilclient/v2/invoices.py b/distilclient/v2/invoices.py
index 92c29aa..2b95a1f 100644
--- a/distilclient/v2/invoices.py
+++ b/distilclient/v2/invoices.py
@@ -12,6 +12,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import datetime
 from distilclient import base
 
 
@@ -28,6 +29,10 @@ class InvoiceManager(base.Manager):
                          usage info in the response.
         :returns: A list of invoices.
         """
+        if isinstance(start, datetime.datetime):
+            start = start.strftime('%Y-%m-%d')
+        if isinstance(end, datetime.datetime):
+            end = end.strftime('%Y-%m-%d')
 
         url = "/v2/invoices?start={0}&end={1}&detailed={2}"
         if project_id: