1 files changed, 8 insertions, 0 deletions
diff --git a/Lib/test/test_configparser.py b/Lib/test/test_configparser.py
index e9b03e6..569959c 100644
--- a/Lib/test/test_configparser.py
+++ b/Lib/test/test_configparser.py
@@ -1048,6 +1048,14 @@ class ConfigParserTestCaseLegacyInterpolation(ConfigParserTestCase):
         self.assertEqual(cf.get("sect", "option2"), "foo%%bar")
 
 
+class ConfigParserTestCaseInvalidInterpolationType(unittest.TestCase):
+    def test_error_on_wrong_type_for_interpolation(self):
+        for value in [configparser.ExtendedInterpolation,  42,  "a string"]:
+            with self.subTest(value=value):
+                with self.assertRaises(TypeError):
+                    configparser.ConfigParser(interpolation=value)
+
+
 class ConfigParserTestCaseNonStandardDelimiters(ConfigParserTestCase):
     delimiters = (':=', '$')
     comment_prefixes = ('//', '"')