diff --git a/letsencrypt/storage.py b/letsencrypt/storage.py
index 9b2b1705a..e41805459 100644
--- a/letsencrypt/storage.py
+++ b/letsencrypt/storage.py
@@ -131,7 +131,9 @@ class RenewableCert(object):  # pylint: disable=too-many-instance-attributes
         self._check_symlinks()
 
     def _check_symlinks(self):
+        """Raises an exception if a symlink doesn't exist"""
         def check(link):
+            """Checks if symlink points to a file that exists"""
             return os.path.exists(os.path.realpath(link))
         for kind in ALL_FOUR:
             if not check(getattr(self, kind)):
diff --git a/letsencrypt/tests/renewer_test.py b/letsencrypt/tests/renewer_test.py
index 4d217cba4..3c8e3cb95 100644
--- a/letsencrypt/tests/renewer_test.py
+++ b/letsencrypt/tests/renewer_test.py
@@ -76,7 +76,7 @@ class BaseRenewableCertTest(unittest.TestCase):
         junk.close()
 
         self.defaults = configobj.ConfigObj()
-        
+
         with mock.patch("letsencrypt.storage.RenewableCert._check_symlinks") as check:
             check.return_value = True
             self.test_rc = storage.RenewableCert(config.filename, self.cli_config)