diff --git a/Misc/NEWS.d/next/Core and Builtins/2022-12-31-23-32-09.gh-issue-100649.C0fY4S.rst b/Misc/NEWS.d/next/Core and Builtins/2022-12-31-23-32-09.gh-issue-100649.C0fY4S.rst
new file mode 100644
index 00000000000..7ee929ad09f
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2022-12-31-23-32-09.gh-issue-100649.C0fY4S.rst	
@@ -0,0 +1 @@
+Update the native_thread_id field of PyThreadState after fork.
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 2dfed7c583c..150bb78cb41 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -591,6 +591,10 @@ PyOS_AfterFork_Child(void)
     PyThreadState *tstate = _PyThreadState_GET();
     _Py_EnsureTstateNotNULL(tstate);
 
+#ifdef PY_HAVE_THREAD_NATIVE_ID
+    tstate->native_thread_id = PyThread_get_thread_native_id();
+#endif
+
     status = _PyEval_ReInitThreads(tstate);
     if (_PyStatus_EXCEPTION(status)) {
         goto fatal_error;