diff --git a/rtorrent/lib/torrentparser.py b/rtorrent/lib/torrentparser.py
index b59ae22..e61f578 100644
--- a/rtorrent/lib/torrentparser.py
+++ b/rtorrent/lib/torrentparser.py
@@ -23,6 +23,9 @@
 import re
 import rtorrent.lib.bencode as bencode
 import hashlib
+import urlparse
+import base64
+import binascii
 
 if is_py3():
     from urllib.request import urlopen  # @UnresolvedImport @UnusedImport
@@ -89,11 +92,27 @@ def _decode_torrent(self, raw_torrent=None):
 
     def _calc_info_hash(self):
         self.info_hash = None
-        if "info" in self._torrent_decoded.keys():
-            info_encoded = bencode.encode(self._torrent_decoded["info"])
-
-            if info_encoded:
-                self.info_hash = hashlib.sha1(info_encoded).hexdigest().upper()
+        if "magnet-uri" in self._torrent_decoded.keys():
+            m = self._torrent_decoded['magnet-uri']
+            mqs=urlparse.parse_qs( urlparse.urlparse(m).query )
+            if 'xt' in mqs:
+                xts = mqs['xt'][0]
+                if xts.startswith( 'urn:btih:' ):
+                    btih = xts[9:]
+                    if len(btih) == 40:
+                        btih = btih.upper()
+                    elif len(btih) == 32:
+                        btih = binascii.b2a_hex(base64.b32decode(btih)).upper()
+                    else:
+                        btih = None
+                    self.info_hash = btih
+
+        if self.info_hash is None:
+            if "info" in self._torrent_decoded.keys():
+                info_encoded = bencode.encode(self._torrent_decoded["info"])
+
+                if info_encoded:
+                    self.info_hash = hashlib.sha1(info_encoded).hexdigest().upper()
 
         return(self.info_hash)