diff --git a/Lib/http/cookies.py b/Lib/http/cookies.py
index e584396caf7..0d9e6d0e3ad 100644
--- a/Lib/http/cookies.py
+++ b/Lib/http/cookies.py
@@ -178,6 +178,11 @@ _Translator       = {
     '\033' : '\\033',  '\034' : '\\034',  '\035' : '\\035',
     '\036' : '\\036',  '\037' : '\\037',
 
+    # Because of the way browsers really handle cookies (as opposed
+    # to what the RFC says) we also encode , and ;
+
+    ',' : '\\054', ';' : '\\073',
+
     '"' : '\\"',       '\\' : '\\\\',
 
     '\177' : '\\177',  '\200' : '\\200',  '\201' : '\\201',
diff --git a/Lib/test/test_http_cookies.py b/Lib/test/test_http_cookies.py
index 99133f79290..cc225cd49d1 100644
--- a/Lib/test/test_http_cookies.py
+++ b/Lib/test/test_http_cookies.py
@@ -65,6 +65,14 @@ class CookieTests(unittest.TestCase):
         </script>
         """)
 
+    def test_extended_encode(self):
+        # Issue 9824: some browsers don't follow the standard; we now
+        # encode , and ; to keep them from tripping up.
+        C = cookies.SimpleCookie()
+        C['val'] = "some,funky;stuff"
+        self.assertEqual(C.output(['val']),
+            'Set-Cookie: val="some\\054funky\\073stuff"')
+
     def test_special_attrs(self):
         # 'expires'
         C = cookies.SimpleCookie('Customer="WILE_E_COYOTE"')
diff --git a/Misc/NEWS b/Misc/NEWS
index d0dd3a19c60..77d776926ea 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -24,6 +24,9 @@ Core and Builtins
 Library
 -------
 
+- Issue 9824: SimpleCookie now encodes , and ; in values to cater to how
+  browsers actually parse cookies.
+
 - Issue #5258/#10642: if site.py encounters a .pth file that generates an error,
   it now prints the filename, line number, and traceback to stderr and skips
   the rest of that individual file, instead of stopping processing entirely.