diff --git a/Misc/NEWS b/Misc/NEWS
index e26a5c0..0a021ea 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -29,6 +29,9 @@
 Library
 -------
 
+- Issue #28200: Fix memory leak on Windows in the os module (fix
+  path_converter() function).
+
 - Issue #25400: RobotFileParser now correctly returns default values for
   crawl_delay and request_rate.  Initial patch by Peter Wirtz.
 
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index ba54249..470ee92 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -920,7 +920,7 @@
 
     if (is_unicode) {
 #ifdef MS_WINDOWS
-        wide = PyUnicode_AsWideCharString(o, &length);
+        wide = PyUnicode_AsUnicodeAndSize(o, &length);
         if (!wide) {
             goto exit;
         }