diff --git a/Lib/test/test_urllib.py b/Lib/test/test_urllib.py
index c74b101..8d41bf0 100644
--- a/Lib/test/test_urllib.py
+++ b/Lib/test/test_urllib.py
@@ -101,7 +101,7 @@
         # Records changes to env vars
         self.env = test_support.EnvironmentVarGuard()
         # Delete all proxy related env vars
-        for k, v in os.environ.iteritems():
+        for k in os.environ.keys():
             if 'proxy' in k.lower():
                 self.env.unset(k)