diff --git a/Lib/posixpath.py b/Lib/posixpath.py
index 4fc02be69bd6e1..c10c80fac34026 100644
--- a/Lib/posixpath.py
+++ b/Lib/posixpath.py
@@ -207,11 +207,14 @@ def ismount(path):
         parent = join(path, b'..')
     else:
         parent = join(path, '..')
-    parent = realpath(parent)
     try:
         s2 = os.lstat(parent)
-    except (OSError, ValueError):
-        return False
+    except OSError:
+        parent = realpath(parent)
+        try:
+            s2 = os.lstat(parent)
+        except OSError:
+            return False
 
     dev1 = s1.st_dev
     dev2 = s2.st_dev
diff --git a/Misc/NEWS.d/next/Library/2024-04-02-11-17-44.gh-issue-117394.2aoSlb.rst b/Misc/NEWS.d/next/Library/2024-04-02-11-17-44.gh-issue-117394.2aoSlb.rst
new file mode 100644
index 00000000000000..7b695be4b35d0c
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2024-04-02-11-17-44.gh-issue-117394.2aoSlb.rst
@@ -0,0 +1 @@
+:func:`os.path.ismount` is now 2-3 times faster if the user has permissions.