diff --git a/Lib/wsgiref/validate.py b/Lib/wsgiref/validate.py
index 49eaa51..6107dcd 100644
--- a/Lib/wsgiref/validate.py
+++ b/Lib/wsgiref/validate.py
@@ -337,7 +337,7 @@
 
     # @@: 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 a6a9a9d..3727f85 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -1207,6 +1207,7 @@
 Dave Sawyer
 Ben Sayer
 sbt
+Luca Sbardella
 Marco Scataglini
 Andrew Schaaf
 Michael Scharf
diff --git a/Misc/NEWS b/Misc/NEWS
index b84e38d..2755a39 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -66,6 +66,8 @@
 Library
 -------
 
+- Issue #17527: Add PATCH to wsgiref.validator. Patch from Luca Sbardella.
+
 - Issue #24683: Fixed crashes in _json functions called with arguments of
   inappropriate type.