diff --git a/master/buildbot/test/util/www.py b/master/buildbot/test/util/www.py
index 9ba2df96a01..9cd93b0879b 100644
--- a/master/buildbot/test/util/www.py
+++ b/master/buildbot/test/util/www.py
@@ -78,6 +78,8 @@ def finish(self):
             self.deferred.callback(self.written)
 
     def setResponseCode(self, code):
+        # twisted > 16 started to assert this
+        assert isinstance(code, (int, long))
         self.responseCode = code
 
     def setHeader(self, hdr, value):
diff --git a/master/buildbot/www/resource.py b/master/buildbot/www/resource.py
index 792fc97c93f..46f81a62734 100644
--- a/master/buildbot/www/resource.py
+++ b/master/buildbot/www/resource.py
@@ -84,7 +84,7 @@ def failHttpRedirect(f):
         def failHttpError(f):
             f.trap(Error)
             e = f.value
-            writeError(e.message, errcode=e.status)
+            writeError(e.message, errcode=int(e.status))
 
         @d.addErrback
         def fail(f):