diff --git a/Lib/posixpath.py b/Lib/posixpath.py
index ecb4e5a8f70..62afbd0ccf0 100644
--- a/Lib/posixpath.py
+++ b/Lib/posixpath.py
@@ -262,6 +262,9 @@ def expanduser(path):
             # password database, return the path unchanged
             return path
         userhome = pwent.pw_dir
+    # if no user home, return the path unchanged on VxWorks
+    if userhome is None and sys.platform == "vxworks":
+        return path
     if isinstance(path, bytes):
         userhome = os.fsencode(userhome)
         root = b'/'
diff --git a/Misc/NEWS.d/next/Library/2020-11-27-18-09-59.bpo-31904.g8k43d.rst b/Misc/NEWS.d/next/Library/2020-11-27-18-09-59.bpo-31904.g8k43d.rst
new file mode 100644
index 00000000000..5a687d1eb32
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2020-11-27-18-09-59.bpo-31904.g8k43d.rst
@@ -0,0 +1,2 @@
+:func:`posixpath.expanduser` returns the input *path* unchanged if
+user home directory is None on VxWorks.