diff --git a/.hgtags b/.hgtags
index ae615cf89e8..a2e89e9581c 100644
--- a/.hgtags
+++ b/.hgtags
@@ -151,3 +151,4 @@ b4cbecbc0781e89a309d03b60a1f75f8499250e6 v3.4.3
 071fefbb5e3db770c6c19fba9994699f121b1cea v3.5.0b1
 7a088af5615bf04024e9912068f4bd8f43ed3917 v3.5.0b2
 0035fcd9b9243ae52c2e830204fd9c1f7d528534 v3.5.0b3
+c0d64105463581f85d0e368e8d6e59b7fd8f12b1 v3.5.0b4
diff --git a/Lib/wsgiref/validate.py b/Lib/wsgiref/validate.py
index 49eaa514cc5..6107dcd7a4d 100644
--- a/Lib/wsgiref/validate.py
+++ b/Lib/wsgiref/validate.py
@@ -337,7 +337,7 @@ def check_environ(environ):
 
     # @@: these need filling out:
     if environ['REQUEST_METHOD'] not in (
-        'GET', 'HEAD', 'POST', 'OPTIONS','PUT','DELETE','TRACE'):
+        'GET', 'HEAD', 'POST', 'OPTIONS', 'PATCH', 'PUT', 'DELETE', 'TRACE'):
         warnings.warn(
             "Unknown REQUEST_METHOD: %r" % environ['REQUEST_METHOD'],
             WSGIWarning)
diff --git a/Misc/ACKS b/Misc/ACKS
index 7e513adae8a..ab7c7d600a8 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -1242,6 +1242,7 @@ Bob Savage
 Dave Sawyer
 Ben Sayer
 sbt
+Luca Sbardella
 Marco Scataglini
 Andrew Schaaf
 Michael Scharf
diff --git a/Misc/NEWS b/Misc/NEWS
index f80221aa961..1e1a88c466a 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -13,6 +13,8 @@ Core and Builtins
 Library
 -------
 
+- Issue #17527: Add PATCH to wsgiref.validator. Patch from Luca Sbardella.
+
 - Issue #13938: 2to3 converts StringTypes to a tuple. Patch from Mark Hammond.
 
 - Issue #2091: open() accepted a 'U' mode string containing '+', but 'U' can
@@ -75,8 +77,8 @@ Library
 
 - Issue #24620: Random.setstate() now validates the value of state last element.
 
-- Issue #22485: Fixed an issue that caused `inspect.getsource` to return incorrect
-  results on nested functions.
+- Issue #22485: Fixed an issue that caused `inspect.getsource` to return
+  incorrect results on nested functions.
 
 - Issue #22153: Improve unittest docs. Patch from Martin Panter and evilzero.