diff --git a/Lib/test/test_threading.py b/Lib/test/test_threading.py
index 96b43936be92cd..d1e88b91646066 100644
--- a/Lib/test/test_threading.py
+++ b/Lib/test/test_threading.py
@@ -1580,6 +1580,14 @@ def test_3_join_in_forked_from_thread(self):
 
             main_thread = threading.current_thread()
             def worker():
+                # fork() must happen before the interpreter starts shutting
+                # down: otherwise the main thread is already marked as
+                # stopped in the parent, the child inherits that state, and
+                # the test below succeeds without testing anything.
+                if not main_thread.is_alive():
+                    print('main thread stopped before fork()',
+                          file=sys.stderr, flush=True)
+                    os._exit(3)
                 childpid = os.fork()
                 if childpid != 0:
                     # parent process
@@ -1595,6 +1603,9 @@ def worker():
 
             w = threading.Thread(target=worker)
             w.start()
+            # Keep the main thread alive until worker() has forked, so that
+            # the check above cannot be lost to interpreter shutdown.
+            w.join()
             """
         self._run_and_join(script)
 
diff --git a/Misc/NEWS.d/next/Tests/2026-09-28-12-05-10.gh-issue-116612.Rn4kLp.rst b/Misc/NEWS.d/next/Tests/2026-09-28-12-05-10.gh-issue-116612.Rn4kLp.rst
new file mode 100644
index 00000000000000..650c51d19f96aa
--- /dev/null
+++ b/Misc/NEWS.d/next/Tests/2026-09-28-12-05-10.gh-issue-116612.Rn4kLp.rst
@@ -0,0 +1,3 @@
+Make ``test_3_join_in_forked_from_thread`` in ``test_threading`` wait for the
+forking thread, so that the fork happens while the main thread is still
+running rather than racing interpreter shutdown.