diff --git a/Lib/robotparser.py b/Lib/robotparser.py
index 447563f..730426f 100644
--- a/Lib/robotparser.py
+++ b/Lib/robotparser.py
@@ -131,7 +131,12 @@
             return True
         # search for given user agent matches
         # the first match counts
-        url = urllib.quote(urlparse.urlparse(urllib.unquote(url))[2]) or "/"
+        parsed_url = urlparse.urlparse(urllib.unquote(url))
+        url = urlparse.urlunparse(('', '', parsed_url.path,
+            parsed_url.params, parsed_url.query, parsed_url.fragment))
+        url = urllib.quote(url)
+        if not url:
+            url = "/"
         for entry in self.entries:
             if entry.applies_to(useragent):
                 return entry.allowance(url)