diff --git a/scrapy/core/downloader/webclient.py b/scrapy/core/downloader/webclient.py
index 2c6a61b8a..add5576ef 100644
--- a/scrapy/core/downloader/webclient.py
+++ b/scrapy/core/downloader/webclient.py
@@ -118,6 +118,9 @@ class ScrapyHTTPClientFactory(HTTPClientFactory):
             self.headers['Content-Length'] = len(self.body)
             # just in case a broken http/1.1 decides to keep connection alive
             self.headers.setdefault("Connection", "close")
+        # Content-Length must be specified in POST method even with no body
+        elif self.method == 'POST':
+            self.headers['Content-Length'] = 0
 
     def _build_response(self, body, request):
         request.meta['download_latency'] = self.headers_time-self.start_time
diff --git a/tests/test_webclient.py b/tests/test_webclient.py
index a16eb1ccf..e0b46286a 100644
--- a/tests/test_webclient.py
+++ b/tests/test_webclient.py
@@ -132,6 +132,18 @@ class ScrapyHTTPPageGetterTests(unittest.TestCase):
             "\r\n"
             "name=value")
 
+        # test a POST method with no body provided
+        factory = client.ScrapyHTTPClientFactory(Request(
+            method='POST',
+            url='http://foo/bar'
+        ))
+
+        self._test(factory,
+                   "POST /bar HTTP/1.0\r\n"
+                   "Host: foo\r\n"
+                   "Content-Length: 0\r\n"
+                   "\r\n")
+
         # test with single and multivalued headers
         factory = client.ScrapyHTTPClientFactory(Request(
             url='http://foo/bar',