diff --git a/src/_pytest/config/__init__.py b/src/_pytest/config/__init__.py
index 5d77fa983a7..3a0eca546a3 100644
--- a/src/_pytest/config/__init__.py
+++ b/src/_pytest/config/__init__.py
@@ -30,16 +30,13 @@
 from _pytest.compat import importlib_metadata
 from _pytest.outcomes import fail
 from _pytest.outcomes import Skipped
+from _pytest.pathlib import unique_path
 from _pytest.warning_types import PytestConfigWarning
 
 hookimpl = HookimplMarker("pytest")
 hookspec = HookspecMarker("pytest")
 
 
-def _uniquepath(path):
-    return type(path)(os.path.normcase(str(path.realpath())))
-
-
 class ConftestImportFailure(Exception):
     def __init__(self, path, excinfo):
         Exception.__init__(self, path, excinfo)
@@ -370,7 +367,7 @@ def _set_initial_conftests(self, namespace):
         """
         current = py.path.local()
         self._confcutdir = (
-            _uniquepath(current.join(namespace.confcutdir, abs=True))
+            unique_path(current.join(namespace.confcutdir, abs=True))
             if namespace.confcutdir
             else None
         )
@@ -409,7 +406,7 @@ def _getconftestmodules(self, path):
         else:
             directory = path
 
-        directory = _uniquepath(directory)
+        directory = unique_path(directory)
 
         # XXX these days we may rather want to use config.rootdir
         # and allow users to opt into looking into the rootdir parent
@@ -438,7 +435,7 @@ def _importconftest(self, conftestpath):
         # Use realpath to avoid loading the same conftest twice
         # with build systems that create build directories containing
         # symlinks to actual files.
-        conftestpath = _uniquepath(conftestpath)
+        conftestpath = unique_path(conftestpath)
         try:
             return self._conftestpath2mod[conftestpath]
         except KeyError:
diff --git a/src/_pytest/pathlib.py b/src/_pytest/pathlib.py
index 19f9c062f89..0403b694737 100644
--- a/src/_pytest/pathlib.py
+++ b/src/_pytest/pathlib.py
@@ -11,6 +11,7 @@
 from os.path import expanduser
 from os.path import expandvars
 from os.path import isabs
+from os.path import normcase
 from os.path import sep
 from posixpath import sep as posix_sep
 
@@ -334,3 +335,12 @@ def fnmatch_ex(pattern, path):
 def parts(s):
     parts = s.split(sep)
     return {sep.join(parts[: i + 1]) or sep for i in range(len(parts))}
+
+
+def unique_path(path):
+    """Returns a unique path in case-insensitive (but case-preserving) file
+    systems such as Windows.
+
+    This is needed only for ``py.path.local``; ``pathlib.Path`` handles this
+    natively with ``resolve()``."""
+    return type(path)(normcase(str(path.realpath())))
diff --git a/testing/test_conftest.py b/testing/test_conftest.py
index a9af649d000..9888f5457f3 100644
--- a/testing/test_conftest.py
+++ b/testing/test_conftest.py
@@ -4,9 +4,9 @@
 import py
 
 import pytest
-from _pytest.config import _uniquepath
 from _pytest.config import PytestPluginManager
 from _pytest.main import ExitCode
+from _pytest.pathlib import unique_path
 
 
 def ConftestWithSetinitial(path):
@@ -143,11 +143,11 @@ def test_conftestcutdir(testdir):
     # but we can still import a conftest directly
     conftest._importconftest(conf)
     values = conftest._getconftestmodules(conf.dirpath())
-    assert values[0].__file__.startswith(str(_uniquepath(conf)))
+    assert values[0].__file__.startswith(str(unique_path(conf)))
     # and all sub paths get updated properly
     values = conftest._getconftestmodules(p)
     assert len(values) == 1
-    assert values[0].__file__.startswith(str(_uniquepath(conf)))
+    assert values[0].__file__.startswith(str(unique_path(conf)))
 
 
 def test_conftestcutdir_inplace_considered(testdir):
@@ -156,7 +156,7 @@ def test_conftestcutdir_inplace_considered(testdir):
     conftest_setinitial(conftest, [conf.dirpath()], confcutdir=conf.dirpath())
     values = conftest._getconftestmodules(conf.dirpath())
     assert len(values) == 1
-    assert values[0].__file__.startswith(str(_uniquepath(conf)))
+    assert values[0].__file__.startswith(str(unique_path(conf)))
 
 
 @pytest.mark.parametrize("name", "test tests whatever .dotdir".split())
@@ -166,7 +166,7 @@ def test_setinitial_conftest_subdirs(testdir, name):
     conftest = PytestPluginManager()
     conftest_setinitial(conftest, [sub.dirpath()], confcutdir=testdir.tmpdir)
     if name not in ("whatever", ".dotdir"):
-        assert _uniquepath(subconftest) in conftest._conftestpath2mod
+        assert unique_path(subconftest) in conftest._conftestpath2mod
         assert len(conftest._conftestpath2mod) == 1
     else:
         assert subconftest not in conftest._conftestpath2mod