diff --git a/swift/obj/server.py b/swift/obj/server.py
index 14b60e10e2..a5f90ef49c 100644
--- a/swift/obj/server.py
+++ b/swift/obj/server.py
@@ -594,13 +594,21 @@ class ObjectController(object):
                 response_class = HTTPNoContent
             else:
                 response_class = HTTPConflict
-        if 'x-if-delete-at' in request.headers and \
-                int(request.headers['x-if-delete-at']) != \
-                int(orig_metadata.get('X-Delete-At') or 0):
-            return HTTPPreconditionFailed(
-                request=request,
-                body='X-If-Delete-At and X-Delete-At do not match')
         orig_delete_at = int(orig_metadata.get('X-Delete-At') or 0)
+        try:
+            req_if_delete_at_val = request.headers['x-if-delete-at']
+            req_if_delete_at = int(req_if_delete_at_val)
+        except KeyError:
+            pass
+        except ValueError:
+            return HTTPBadRequest(
+                request=request,
+                body='Bad X-If-Delete-At header value')
+        else:
+            if orig_delete_at != req_if_delete_at:
+                return HTTPPreconditionFailed(
+                    request=request,
+                    body='X-If-Delete-At and X-Delete-At do not match')
         if orig_delete_at:
             self.delete_at_update('DELETE', orig_delete_at, account,
                                   container, obj, request, device)
diff --git a/test/functionalnosetests/test_object.py b/test/functionalnosetests/test_object.py
index 97cd8d0f26..dad8635da9 100755
--- a/test/functionalnosetests/test_object.py
+++ b/test/functionalnosetests/test_object.py
@@ -581,6 +581,28 @@ class TestObject(unittest.TestCase):
         self.assertEquals(resp.getheader('Content-Type'),
                           'text/html; charset=UTF-8')
 
+    def test_delete_if_delete_at_bad(self):
+        if skip:
+            raise SkipTest
+
+        def put(url, token, parsed, conn):
+            conn.request('PUT',
+                         '%s/%s/hi-delete-bad' % (parsed.path, self.container),
+                         'there', {'X-Auth-Token': token})
+            return check_response(conn)
+        resp = retry(put)
+        resp.read()
+        self.assertEquals(resp.status, 201)
+
+        def delete(url, token, parsed, conn):
+            conn.request('DELETE', '%s/%s/hi' % (parsed.path, self.container),
+                         '', {'X-Auth-Token': token,
+                              'X-If-Delete-At': 'bad'})
+            return check_response(conn)
+        resp = retry(delete)
+        resp.read()
+        self.assertEquals(resp.status, 400)
+
     def test_null_name(self):
         if skip:
             raise SkipTest
diff --git a/test/unit/obj/test_server.py b/test/unit/obj/test_server.py
index 078557df45..fb25f12abb 100755
--- a/test/unit/obj/test_server.py
+++ b/test/unit/obj/test_server.py
@@ -2840,6 +2840,13 @@ class TestObjectController(unittest.TestCase):
         resp = req.get_response(self.object_controller)
         self.assertEquals(resp.status_int, 204)
 
+        req = Request.blank(
+            '/sda1/p/a/c/o', environ={'REQUEST_METHOD': 'DELETE'},
+            headers={'X-Timestamp': normalize_timestamp(test_time - 92),
+                     'X-If-Delete-At': 'abc'})
+        resp = req.get_response(self.object_controller)
+        self.assertEquals(resp.status_int, 400)
+
     def test_DELETE_calls_delete_at(self):
         given_args = []