diff --git a/readthedocs/core/middleware.py b/readthedocs/core/middleware.py
index 692e45a2f8d..d62d93b1702 100644
--- a/readthedocs/core/middleware.py
+++ b/readthedocs/core/middleware.py
@@ -61,7 +61,7 @@ def process_request(self, request):
         # Serve CNAMEs
         if (
             public_domain not in host and
-            settings.PRODUCTION_DOMAIN not in host and
+            settings.PRODUCTION_DOMAIN not in (host, full_host) and
             'localhost' not in host and
             'testserver' not in host
         ):