diff --git a/Lib/test/test_urllib.py b/Lib/test/test_urllib.py
index 3fcf9a3f0c2..7d35f10b123 100644
--- a/Lib/test/test_urllib.py
+++ b/Lib/test/test_urllib.py
@@ -135,7 +135,9 @@ def test_getproxies_environment_keep_no_proxies(self):
         proxies = urllib.request.getproxies_environment()
         # getproxies_environment use lowered case truncated (no '_proxy') keys
         self.assertEqual('localhost', proxies['no'])
-
+        # List of no_proxies with space.
+        self.env.set('NO_PROXY', 'localhost, anotherdomain.com, newdomain.com')
+        self.assertTrue(urllib.request.proxy_bypass_environment('anotherdomain.com'))
 
 class urlopen_HttpTests(unittest.TestCase):
     """Test urlopen() opening a fake http connection."""
diff --git a/Lib/urllib/request.py b/Lib/urllib/request.py
index d1acae1b568..4a571e8b9f6 100644
--- a/Lib/urllib/request.py
+++ b/Lib/urllib/request.py
@@ -2274,7 +2274,8 @@ def proxy_bypass_environment(host):
     # strip port off host
     hostonly, port = splitport(host)
     # check if the host ends with any of the DNS suffixes
-    for name in no_proxy.split(','):
+    no_proxy_list = [proxy.strip() for proxy in no_proxy.split(',')]
+    for name in no_proxy_list:
         if name and (hostonly.endswith(name) or host.endswith(name)):
             return 1
     # otherwise, don't bypass