diff --git a/docs/news.rst b/docs/news.rst
index 670843e0e..a5cc6c723 100644
--- a/docs/news.rst
+++ b/docs/news.rst
@@ -2042,6 +2042,13 @@ Backward-incompatible changes
     ``process_start_requests()`` has been replaced by ``process_start()``.
     (:issue:`6729`)
 
+-   The ``scrape_func`` callable passed to
+    ``scrapy.core.spidermw.SpiderMiddlewareManager.scrape_response()`` is now
+    called with 2 parameters, ``response`` and ``request``, instead of 3, and
+    must return a :class:`~twisted.internet.defer.Deferred` instead of an
+    iterable.
+    (:issue:`6787`)
+
 -   The now-deprecated ``start_requests()`` method, when it returns an iterable
     instead of being defined as a generator, is now executed *after* the
     :ref:`scheduler <topics-scheduler>` instance has been created.
diff --git a/docs/topics/signals.rst b/docs/topics/signals.rst
index 8f0f4d8e9..f7f9f5cca 100644
--- a/docs/topics/signals.rst
+++ b/docs/topics/signals.rst
@@ -26,6 +26,7 @@ Here is a simple example showing how you can catch signals and perform some acti
 
     class DmozSpider(Spider):
         name = "dmoz"
+        allowed_domains = ["dmoz.org"]
         start_urls = [
             "http://www.dmoz.org/Computers/Programming/Languages/Python/Books/",
             "http://www.dmoz.org/Computers/Programming/Languages/Python/Resources/",