diff --git a/django/http/__init__.py b/django/http/__init__.py
index 62415da3c6..930e84cddc 100644
--- a/django/http/__init__.py
+++ b/django/http/__init__.py
@@ -676,7 +676,7 @@ class HttpResponse(object):
         return b''.join([smart_bytes(e, self._charset) for e in self._container])
 
     def _set_content(self, value):
-        if hasattr(value, '__iter__') and not isinstance(value, six.string_types):
+        if hasattr(value, '__iter__') and not isinstance(value, (bytes, six.string_types)):
             self._container = value
             self._base_content_is_iter = True
         else: