diff --git a/Lib/urllib2.py b/Lib/urllib2.py
index 058397d..60ff260 100644
--- a/Lib/urllib2.py
+++ b/Lib/urllib2.py
@@ -281,7 +281,7 @@
     def header_items(self):
         hdrs = self.unredirected_hdrs.copy()
         hdrs.update(self.headers)
-        return hdrs.items()
+        return list(hdrs.items())
 
 class OpenerDirector:
     def __init__(self):
@@ -710,7 +710,7 @@
         domains = self.passwd.get(realm, {})
         for default_port in True, False:
             reduced_authuri = self.reduce_uri(authuri, default_port)
-            for uris, authinfo in domains.iteritems():
+            for uris, authinfo in domains.items():
                 for uri in uris:
                     if self.is_suburi(uri, reduced_authuri):
                         return authinfo
@@ -1318,21 +1318,21 @@
         # first check for old ones
         t = time.time()
         if self.soonest <= t:
-            for k, v in self.timeout.items():
+            for k, v in list(self.timeout.items()):
                 if v < t:
                     self.cache[k].close()
                     del self.cache[k]
                     del self.timeout[k]
-        self.soonest = min(self.timeout.values())
+        self.soonest = min(list(self.timeout.values()))
 
         # then check the size
         if len(self.cache) == self.max_conns:
-            for k, v in self.timeout.items():
+            for k, v in list(self.timeout.items()):
                 if v == self.soonest:
                     del self.cache[k]
                     del self.timeout[k]
                     break
-            self.soonest = min(self.timeout.values())
+            self.soonest = min(list(self.timeout.values()))
 
 class GopherHandler(BaseHandler):
     def gopher_open(self, req):