Index: Lib/configparser.py
===================================================================
--- Lib/configparser.py	(revision 88694)
+++ Lib/configparser.py	(working copy)
@@ -626,6 +626,8 @@
         self._empty_lines_in_values = empty_lines_in_values
         if interpolation is _UNSET:
             self._interpolation = self._DEFAULT_INTERPOLATION
+        elif interpolation is None:
+            self._interpolation = Interpolation()
         else:
             self._interpolation = interpolation
         self.default_section=default_section
Index: Lib/test/test_configparser.py
===================================================================
--- Lib/test/test_configparser.py	(revision 88694)
+++ Lib/test/test_configparser.py	(working copy)
@@ -858,6 +858,17 @@
         cf = self.newconfig()
         self.assertRaises(ValueError, cf.add_section, self.default_section)
 
+class ConfigParserTestCaseNoInterpolation(BasicTestCase):
+    config_class = configparser.ConfigParser
+    interpolation = None
+
+    def test_init_takes_interpolation_none(self):
+        # Issue 11324
+        p = configparser.ConfigParser(interpolation=None)
+        # The next line raises an exception if ConfigParser doesn't
+        # handle interpolation=None correctly.
+        self.assertIs(p.read_string(""), None)
+
 class ConfigParserTestCaseLegacyInterpolation(ConfigParserTestCase):
     config_class = configparser.ConfigParser
     interpolation = configparser.LegacyInterpolation()
@@ -1327,6 +1338,7 @@
         ConfigParserTestCaseNoValue,
         ConfigParserTestCaseExtendedInterpolation,
         ConfigParserTestCaseLegacyInterpolation,
+        ConfigParserTestCaseNoInterpolation,
         ConfigParserTestCaseTrickyFile,
         MultilineValuesTestCase,
         RawConfigParserTestCase,