diff --git a/Lib/urllib2.py b/Lib/urllib2.py
index db7ce81..0bb69a0 100644
--- a/Lib/urllib2.py
+++ b/Lib/urllib2.py
@@ -556,10 +556,11 @@
         newurl = urlparse.urljoin(req.get_full_url(), newurl)
 
         # For security reasons we do not allow redirects to protocols
-        # other than HTTP or HTTPS.
+        # other than HTTP, HTTPS or FTP.
         newurl_lower = newurl.lower()
         if not (newurl_lower.startswith('http://') or
-                newurl_lower.startswith('https://')):
+                newurl_lower.startswith('https://') or
+                newurl_lower.startswith('ftp://')):
             return
 
         # XXX Probably want to forget about the state of the current