diff --git a/Lib/ConfigParser.py b/Lib/ConfigParser.py
index 5f80269..acbf3ea 100644
--- a/Lib/ConfigParser.py
+++ b/Lib/ConfigParser.py
@@ -202,10 +202,10 @@
 class RawConfigParser:
     def __init__(self, defaults=None):
         self._sections = {}
-        if defaults is None:
-            self._defaults = {}
-        else:
-            self._defaults = defaults
+        self._defaults = {}
+        if defaults:
+            for key, value in defaults.items():
+                self._defaults[self.optionxform(key)] = value
 
     def defaults(self):
         return self._defaults
@@ -511,8 +511,9 @@
             if section != DEFAULTSECT:
                 raise NoSectionError(section)
         # Update with the entry specific variables
-        if vars is not None:
-            d.update(vars)
+        if vars:
+            for key, value in vars.items():
+                d[self.optionxform(key)] = value
         option = self.optionxform(option)
         try:
             value = d[option]
@@ -544,7 +545,8 @@
                 raise NoSectionError(section)
         # Update with the entry specific variables
         if vars:
-            d.update(vars)
+            for key, value in vars.items():
+                d[self.optionxform(key)] = value
         options = d.keys()
         if "__name__" in options:
             options.remove("__name__")
diff --git a/Lib/test/test_cfgparser.py b/Lib/test/test_cfgparser.py
index c799c7d..6b3e68a 100644
--- a/Lib/test/test_cfgparser.py
+++ b/Lib/test/test_cfgparser.py
@@ -115,6 +115,16 @@
         self.failUnless(cf.has_option("section", "Key"))
 
 
+    def test_default_case_sensitivity(self):
+        cf = self.newconfig({"foo": "Bar"})
+        self.assertEqual(
+            cf.get("DEFAULT", "Foo"), "Bar",
+            "could not locate option, expecting case-insensitive option names")
+        cf = self.newconfig({"Foo": "Bar"})
+        self.assertEqual(
+            cf.get("DEFAULT", "Foo"), "Bar",
+            "could not locate option, expecting case-insensitive defaults")
+
     def test_parse_errors(self):
         self.newconfig()
         self.parse_error(ConfigParser.ParsingError,