diff --git a/httplib2/__init__.py b/httplib2/__init__.py
index e6805e6..fd4c768 100644
--- a/httplib2/__init__.py
+++ b/httplib2/__init__.py
@@ -795,7 +795,7 @@
         else:
             cachekey = None
                     
-        if method in ["PUT"] and self.cache and info.has_key('etag') and not self.ignore_etag:
+        if method in ["PUT"] and self.cache and info.has_key('etag') and not self.ignore_etag and 'if-match' not in headers:
             # http://www.w3.org/1999/04/Editing/ 
             headers['if-match'] = info['etag']
 
@@ -830,9 +830,9 @@
                     return (response, content)
 
                 if entry_disposition == "STALE":
-                    if info.has_key('etag') and not self.ignore_etag:
+                    if info.has_key('etag') and not self.ignore_etag and not 'if-none-match' in headers:
                         headers['if-none-match'] = info['etag']
-                    if info.has_key('last-modified'):
+                    if info.has_key('last-modified') and not 'last-modified' in headers:
                         headers['if-modified-since'] = info['last-modified']
                 elif entry_disposition == "TRANSPARENT":
                     pass
diff --git a/httplib2test.py b/httplib2test.py
index 5a7aeff..edda403 100755
--- a/httplib2test.py
+++ b/httplib2test.py
@@ -321,6 +321,21 @@
         self.assertEqual(response.fromcache, False)
         self.assertFalse(d.has_key('HTTP_IF_NONE_MATCH')) 
 
+    def testOverrideEtag(self):
+        # Test that we can forcibly ignore ETags 
+        uri = urlparse.urljoin(base, "reflector/reflector.cgi")
+        (response, content) = self.http.request(uri, "GET")
+        self.assertNotEqual(response['etag'], "")
+
+        (response, content) = self.http.request(uri, "GET", headers = {'cache-control': 'max-age=0'})
+        d = self.reflector(content)
+        self.assertTrue(d.has_key('HTTP_IF_NONE_MATCH')) 
+        self.assertNotEqual(d['HTTP_IF_NONE_MATCH'], "fred") 
+
+        (response, content) = self.http.request(uri, "GET", headers = {'cache-control': 'max-age=0', 'if=none-match': 'fred'})
+        d = self.reflector(content)
+        self.assertTrue(d.has_key('HTTP_IF_NONE_MATCH')) 
+        self.assertEqual(d['HTTP_IF_NONE_MATCH'], "fred") 
 
     def testGet304EndToEnd(self):
        # Test that end to end headers get overwritten in the cache
@@ -513,6 +528,21 @@
         (response, content) = self.http.request(uri, "PUT")
         self.assertEqual(response.status, 412)
 
+    def testUpdateUsesCachedETagOverridden(self):
+        # Test that we natively support http://www.w3.org/1999/04/Editing/ 
+        uri = urlparse.urljoin(base, "conditional-updates/test.cgi")
+
+        (response, content) = self.http.request(uri, "GET")
+        self.assertEqual(response.status, 200)
+        self.assertEqual(response.fromcache, False)
+        (response, content) = self.http.request(uri, "GET")
+        self.assertEqual(response.status, 200)
+        self.assertEqual(response.fromcache, True)
+        (response, content) = self.http.request(uri, "PUT", headers={'if-match': 'fred'})
+        self.assertEqual(response.status, 412)
+
+
+
     def testBasicAuth(self):
         # Test Basic Authentication
         uri = urlparse.urljoin(base, "basic/file.txt")