diff --git a/swift/common/swob.py b/swift/common/swob.py
index 9ec57a026e..916fc667cf 100644
--- a/swift/common/swob.py
+++ b/swift/common/swob.py
@@ -281,6 +281,11 @@ class HeaderKeyDict(dict):
     def get(self, key, default=None):
         return dict.get(self, key.title(), default)
 
+    def setdefault(self, key, value=None):
+        if key not in self:
+            self[key] = value
+        return self[key]
+
 
 def _resp_status_property():
     """
diff --git a/swift/proxy/controllers/base.py b/swift/proxy/controllers/base.py
index 39f61c3d49..a8dc534b05 100644
--- a/swift/proxy/controllers/base.py
+++ b/swift/proxy/controllers/base.py
@@ -473,8 +473,7 @@ class Controller(object):
         headers = HeaderKeyDict(additional) if additional else HeaderKeyDict()
         if transfer:
             self.transfer_headers(orig_req.headers, headers)
-        if 'x-timestamp' not in headers:
-            headers['x-timestamp'] = normalize_timestamp(time.time())
+        headers.setdefault('x-timestamp', normalize_timestamp(time.time()))
         if orig_req:
             referer = orig_req.as_referer()
         else:
diff --git a/test/unit/common/test_swob.py b/test/unit/common/test_swob.py
index e4ff0ff980..fd461ac261 100644
--- a/test/unit/common/test_swob.py
+++ b/test/unit/common/test_swob.py
@@ -81,6 +81,23 @@ class TestHeaderKeyDict(unittest.TestCase):
         self.assertEquals(headers['content-length'], '20')
         self.assertEquals(headers['CONTENT-LENGTH'], '20')
 
+    def test_setdefault(self):
+        headers = swift.common.swob.HeaderKeyDict()
+
+        # it gets set
+        headers.setdefault('x-rubber-ducky', 'the one')
+        self.assertEquals(headers['X-Rubber-Ducky'], 'the one')
+
+        # it has the right return value
+        ret = headers.setdefault('x-boat', 'dinghy')
+        self.assertEquals(ret, 'dinghy')
+
+        ret = headers.setdefault('x-boat', 'yacht')
+        self.assertEquals(ret, 'dinghy')
+
+        # shouldn't crash
+        headers.setdefault('x-sir-not-appearing-in-this-request', None)
+
     def test_del_contains(self):
         headers = swift.common.swob.HeaderKeyDict()
         headers['Content-Length'] = 0