diff -r 325aec842e3e Lib/httplib.py
--- a/Lib/httplib.py	Wed Feb 25 10:12:26 2015 -0500
+++ b/Lib/httplib.py	Fri Feb 27 22:08:31 2015 +0000
@@ -1005,19 +1005,30 @@
         """Send a complete request to the server."""
         self._send_request(method, url, body, headers)
 
-    def _set_content_length(self, body):
-        # Set the content-length based on the body.
+    def _set_content_length(self, body, method):
+        # Set the content-length based on the body. If the body is "empty", we
+        # set Content-Length: 0 for methods that expect a body (RFC 7230,
+        # Section 3.3.2). If the body is set for other methods, we set the
+        # header provided we can figure out what the length is.
         thelen = None
-        try:
-            thelen = str(len(body))
-        except TypeError, te:
-            # If this is a file-like object, try to
-            # fstat its file descriptor
+
+        method_expects_body = (
+            method.upper() in ('OPTIONS', 'PATCH', 'POST', 'PUT')
+        )
+
+        if body is None and method_expects_body:
+            thelen = 0
+        elif body is not None:
             try:
-                thelen = str(os.fstat(body.fileno()).st_size)
-            except (AttributeError, OSError):
-                # Don't send a length if this failed
-                if self.debuglevel > 0: print "Cannot stat!!"
+                thelen = str(len(body))
+            except TypeError, te:
+                # If this is a file-like object, try to
+                # fstat its file descriptor
+                try:
+                    thelen = str(os.fstat(body.fileno()).st_size)
+                except (AttributeError, OSError):
+                    # Don't send a length if this failed
+                    if self.debuglevel > 0: print "Cannot stat!!"
 
         if thelen is not None:
             self.putheader('Content-Length', thelen)
@@ -1033,8 +1044,8 @@
 
         self.putrequest(method, url, **skips)
 
-        if body is not None and 'content-length' not in header_names:
-            self._set_content_length(body)
+        if 'content-length' not in header_names:
+            self._set_content_length(body, method)
         for hdr, value in headers.iteritems():
             self.putheader(hdr, value)
         self.endheaders(body)
diff -r 325aec842e3e Lib/test/test_httplib.py
--- a/Lib/test/test_httplib.py	Wed Feb 25 10:12:26 2015 -0500
+++ b/Lib/test/test_httplib.py	Fri Feb 27 22:08:31 2015 +0000
@@ -1,4 +1,5 @@
 import httplib
+import itertools
 import array
 import StringIO
 import socket
@@ -122,21 +123,14 @@
                     self.content_length = kv[1].strip()
                 list.append(self, item)
 
-        # POST with empty body
-        conn = httplib.HTTPConnection('example.com')
-        conn.sock = FakeSocket(None)
-        conn._buffer = ContentLengthChecker()
-        conn.request('POST', '/', '')
-        self.assertEqual(conn._buffer.content_length, '0',
-                        'Header Content-Length not set')
-
-        # PUT request with empty body
-        conn = httplib.HTTPConnection('example.com')
-        conn.sock = FakeSocket(None)
-        conn._buffer = ContentLengthChecker()
-        conn.request('PUT', '/', '')
-        self.assertEqual(conn._buffer.content_length, '0',
-                        'Header Content-Length not set')
+        methods = ('PUT', 'POST', 'PATCH', 'OPTIONS')
+        for method, body in itertools.product(methods, [None, '']):
+            conn = httplib.HTTPConnection('example.com')
+            conn.sock = FakeSocket(None)
+            conn._buffer = ContentLengthChecker()
+            conn.request(method, '/', body)
+            self.assertEqual(conn._buffer.content_length, '0',
+                            'Header Content-Length not set')
 
     def test_putheader(self):
         conn = httplib.HTTPConnection('example.com')