diff --git a/Lib/configparser.py b/Lib/configparser.py
index 33dc9b9046f102..a681d3990e7261 100644
--- a/Lib/configparser.py
+++ b/Lib/configparser.py
@@ -846,6 +846,7 @@ def items(self, section=_UNSET, raw=False, vars=None):
         except KeyError:
             if section != self.default_section:
                 raise NoSectionError(section)
+        orig_keys = list(d.keys())
         # Update with the entry specific variables
         if vars:
             for key, value in vars.items():
@@ -854,7 +855,7 @@ def items(self, section=_UNSET, raw=False, vars=None):
             section, option, d[option], d)
         if raw:
             value_getter = lambda option: d[option]
-        return [(option, value_getter(option)) for option in d.keys()]
+        return [(option, value_getter(option)) for option in orig_keys]
 
     def popitem(self):
         """Remove a section from the parser and return it as
diff --git a/Lib/test/test_configparser.py b/Lib/test/test_configparser.py
index 4d07203b9dac28..87b811f09b6ead 100644
--- a/Lib/test/test_configparser.py
+++ b/Lib/test/test_configparser.py
@@ -915,8 +915,7 @@ def test_items(self):
         self.check_items_config([('default', '<default>'),
                                  ('getdefault', '|<default>|'),
                                  ('key', '|value|'),
-                                 ('name', 'value'),
-                                 ('value', 'value')])
+                                 ('name', 'value')])
 
     def test_safe_interpolation(self):
         # See http://www.python.org/sf/511737
@@ -1093,8 +1092,7 @@ def test_items(self):
         self.check_items_config([('default', '<default>'),
                                  ('getdefault', '|%(default)s|'),
                                  ('key', '|%(name)s|'),
-                                 ('name', '%(value)s'),
-                                 ('value', 'value')])
+                                 ('name', '%(value)s')])
 
     def test_set_nonstring_types(self):
         cf = self.newconfig()
diff --git a/Misc/NEWS.d/next/Library/2018-04-23-18-25-36.bpo-33251.C_K-J9.rst b/Misc/NEWS.d/next/Library/2018-04-23-18-25-36.bpo-33251.C_K-J9.rst
new file mode 100644
index 00000000000000..fc6861f0d368ec
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2018-04-23-18-25-36.bpo-33251.C_K-J9.rst
@@ -0,0 +1,2 @@
+`ConfigParser.items()` was fixed so that key-value pairs passed in via `vars`
+are not included in the resulting output.