diff --git a/Lib/ntpath.py b/Lib/ntpath.py
index 6b656976a48..3d9e2009d89 100644
--- a/Lib/ntpath.py
+++ b/Lib/ntpath.py
@@ -204,7 +204,7 @@ def splitdrive(p):
     empty = _get_empty(p)
     if len(p) > 1:
         sep = _get_sep(p)
-        normp = normcase(p)
+        normp = p.replace(_get_altsep(p), sep)
         if (normp[0:2] == sep*2) and (normp[2:3] != sep):
             # is a UNC path:
             # vvvvvvvvvvvvvvvvvvvv drive letter or UNC path
diff --git a/Lib/test/test_ntpath.py b/Lib/test/test_ntpath.py
index 0991d15b9ae..767a5b14a20 100644
--- a/Lib/test/test_ntpath.py
+++ b/Lib/test/test_ntpath.py
@@ -66,6 +66,9 @@ class TestNtpath(unittest.TestCase):
                ('', '\\\\conky\\\\mountpoint\\foo\\bar'))
         tester('ntpath.splitdrive("//conky//mountpoint/foo/bar")',
                ('', '//conky//mountpoint/foo/bar'))
+        # Issue #19911: UNC part containing U+0130
+        self.assertEqual(ntpath.splitdrive('//conky/MOUNTPOİNT/foo/bar'),
+                         ('//conky/MOUNTPOİNT', '/foo/bar'))
 
     def test_split(self):
         tester('ntpath.split("c:\\foo\\bar")', ('c:\\foo', 'bar'))
diff --git a/Misc/NEWS b/Misc/NEWS
index 3819d6cb7a7..0ccc45cfc40 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -44,6 +44,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #19911: ntpath.splitdrive() now correctly processes the 'İ' character
+  (U+0130, LATIN CAPITAL LETTER I WITH DOT ABOVE).
+
 - Issue #19532: python -m compileall with no filename/directory arguments now
   respects the -f and -q flags instead of ignoring them.