diff --git a/Source/WebKit/ChangeLog b/Source/WebKit/ChangeLog
index 4383550e8082..026e18736215 100644
--- a/Source/WebKit/ChangeLog
+++ b/Source/WebKit/ChangeLog
@@ -1,3 +1,21 @@
+2017-08-23  Chris Dumez  <cdumez@apple.com>
+
+        Regression(r221059): NetworkDataTask::didReceiveResponse() should not use PolicyUse for HTTP/0.9
+        https://bugs.webkit.org/show_bug.cgi?id=175872
+
+        Reviewed by Daniel Bates.
+
+        r221059 was calling the ResponseCompletionHandler with {} which ended up being
+        PolicyUse. Since this is an error case and do not want to receive the data, it
+        makes more sense to use PolicyIgnore instead. There should not be a behavior
+        change on WebKit side though since we are cancelling the load right after
+        calling the completion handler anyway.
+
+        Tests under http/tests/security/http-0.9/ are still passing.
+
+        * NetworkProcess/NetworkDataTask.cpp:
+        (WebKit::NetworkDataTask::didReceiveResponse):
+
 2017-08-22  Chris Dumez  <cdumez@apple.com>
 
         Introduce a new CompletionHandler type and use it for NetworkDataTaskClient's completion handlers to help catch bugs
diff --git a/Source/WebKit/NetworkProcess/NetworkDataTask.cpp b/Source/WebKit/NetworkProcess/NetworkDataTask.cpp
index a033dc4a48ec..eaae3da8e8c3 100644
--- a/Source/WebKit/NetworkProcess/NetworkDataTask.cpp
+++ b/Source/WebKit/NetworkProcess/NetworkDataTask.cpp
@@ -103,7 +103,7 @@ void NetworkDataTask::didReceiveResponse(ResourceResponse&& response, ResponseCo
         auto url = response.url();
         std::optional<uint16_t> port = url.port();
         if (port && !isDefaultPortForProtocol(port.value(), url.protocol())) {
-            completionHandler({ });
+            completionHandler(PolicyIgnore);
             cancel();
             m_client->didCompleteWithError({ String(), 0, url, "Cancelled load from '" + url.stringCenterEllipsizedToLength() + "' because it is using HTTP/0.9." });
             return;