--- a/changes/hgpoller.py
+++ b/changes/hgpoller.py
@@ -281,24 +281,23 @@ class BaseHgPoller(BasePoller):
             # if self.verbose:
                 # log.msg("%s has been reset" % self.baseURL)
             # self.lastChangeset = None
             # self.emptyRepo = True
         return self.super_class.dataFailed(self, res)
 
     def processData(self, query):
         push_data = parse_pushlog_json(query)
-        if not push_data['pushes']:
-            if self.lastChangeset is None:
-                # We don't have a lastChangeset, and there are no changes.  Assume
-                # the repository is empty.
-                self.emptyRepo = True
-                if self.verbose:
-                    log.msg("%s is empty" % self.baseURL)
-            # Nothing else to do
+
+        # The payload tells us the most recent push ID. If it is the empty
+        # string, the pushlog is empty and there is no data to consume.
+        if not push_data['lastpushid']:
+            self.emptyRepo = True
+            if self.verbose:
+                log.msg('%s is empty' % self.baseURL)
             return
 
         # We want to add at most self.maxChanges changes per push. If
         # mergePushChanges is True, then we'll get up to maxChanges pushes,
         # each with up to maxChanges changes.
         # Go through the list of pushes backwards, since we want to keep the
         # latest ones and possibly discard earlier ones.
         change_list = []

--- a/test/test_hgpoller.py
+++ b/test/test_hgpoller.py
@@ -326,16 +326,27 @@ class PollingTest(unittest.TestCase):
                 changes.append(change)
 
         p = TestPoller()
         p.parent = parent()
         p.processData(data)
         return p
 
 
+class EmptyLastPushID(PollingTest):
+    def testEmptyLastPushID(self):
+        poller = self.doTest(data="""
+        {
+            "lastpushid": "",
+            "pushes": {}
+        }
+        """)
+        self.assertTrue(poller.emptyRepo, 'repo marked as empty')
+
+
 class RepoBranchHandling(PollingTest):
     def testNoRepoBranch(self):
         self.doTest(repo_branch=None)
 
         self.assertEquals(len(self.changes), 2)
 
     def testDefaultRepoBranch(self):
         self.doTest(repo_branch='default')