coder46
diff --git a/‎scrapy/http/request/form.py
+3-2 b/‎scrapy/http/request/form.py
+3-2
diff --git a/‎scrapy/tests/test_http_request.py
+9-1 b/‎scrapy/tests/test_http_request.py
+9-1
@@ -49,7 +49,8 @@ def _get_form(response, formname, formnumber):
     """Find the form element """
     from scrapy.selector.lxmldocument import LxmlDocument
     root = LxmlDocument(response, lxml.html.HTMLParser)
-    if not root.forms:
+    forms = root.xpath('//form')
+    if not forms:
         raise ValueError("No <form> element found in %s" % response)
 
     if formname is not None:
@@ -61,7 +62,7 @@ def _get_form(response, formname, formnumber):
     # or invalid
     if formnumber is not None:
         try:
-            form = root.forms[formnumber]
+            form = forms[formnumber]
         except IndexError:
             raise IndexError("Form number %d not found in %s" %
                                 (formnumber, response))
 
@@ -116,7 +116,7 @@ def test_ajax_url(http://github.com/self):
 
     def test_copy(self):
         """Test Request copy"""
-        
+
         def somecallback():
             pass
 
@@ -400,6 +400,14 @@ def test_from_response_errors_noform(self):
         response = _buildresponse("""<html></html>""")
         self.assertRaises(ValueError, self.request_class.from_response, response)
 
+    def test_from_response_invalid_html5(self):
+        response = _buildresponse("""<!DOCTYPE html><body></html><form>"""
+                                  """<input type="text" name="foo" value="xxx">"""
+                                  """</form></body></html>""")
+        req = self.request_class.from_response(response, formdata={'bar': 'buz'})
+        fs = _qs(req)
+        self.assertEqual(fs, {'foo': ['xxx'], 'bar': ['buz']})
+
     def test_from_response_errors_formnumber(self):
         response = _buildresponse(
             """<form action="get.php" method="GET">