diff --git a/Doc/distutils/index.rst b/Doc/distutils/index.rst
index b3a52317699..c8dd9f46a8c 100644
--- a/Doc/distutils/index.rst
+++ b/Doc/distutils/index.rst
@@ -20,7 +20,6 @@ very little overhead for build/release/install mechanics.
 
 .. toctree::
    :maxdepth: 2
-   :numbered:
 
    introduction.rst
    setupscript.rst
diff --git a/Doc/library/packaging.rst b/Doc/library/packaging.rst
index 5bf2c06ad9d..c6bff47015e 100644
--- a/Doc/library/packaging.rst
+++ b/Doc/library/packaging.rst
@@ -23,7 +23,6 @@ Building blocks
 
 .. toctree::
    :maxdepth: 2
-   :numbered:
 
    packaging-misc
    packaging.version
@@ -42,7 +41,6 @@ The command machinery
 
 .. toctree::
    :maxdepth: 2
-   :numbered:
 
    packaging.dist
    packaging.command
@@ -55,7 +53,6 @@ Other utilities
 
 .. toctree::
    :maxdepth: 2
-   :numbered:
 
    packaging.util
    packaging.tests.pypi_server
diff --git a/Lib/test/test_concurrent_futures.py b/Lib/test/test_concurrent_futures.py
index fda6f5b807e..222bd5478fc 100644
--- a/Lib/test/test_concurrent_futures.py
+++ b/Lib/test/test_concurrent_futures.py
@@ -623,16 +623,20 @@ class FutureTests(unittest.TestCase):
 
         self.assertTrue(isinstance(f1.exception(timeout=5), IOError))
 
+@test.support.reap_threads
 def test_main():
-    test.support.run_unittest(ProcessPoolExecutorTest,
-                              ThreadPoolExecutorTest,
-                              ProcessPoolWaitTests,
-                              ThreadPoolWaitTests,
-                              ProcessPoolAsCompletedTests,
-                              ThreadPoolAsCompletedTests,
-                              FutureTests,
-                              ProcessPoolShutdownTest,
-                              ThreadPoolShutdownTest)
+    try:
+        test.support.run_unittest(ProcessPoolExecutorTest,
+                                  ThreadPoolExecutorTest,
+                                  ProcessPoolWaitTests,
+                                  ThreadPoolWaitTests,
+                                  ProcessPoolAsCompletedTests,
+                                  ThreadPoolAsCompletedTests,
+                                  FutureTests,
+                                  ProcessPoolShutdownTest,
+                                  ThreadPoolShutdownTest)
+    finally:
+        test.support.reap_children()
 
 if __name__ == "__main__":
     test_main()
diff --git a/Misc/NEWS b/Misc/NEWS
index 93ae3ee9be6..1565d72a12e 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -228,6 +228,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #11321: Fix a crash with multiple imports of the _pickle module when
+  embedding Python.  Patch by Andreas Stührk.
+
 - Issue #6755: Add get_wch() method to curses.window class. Patch by Iñigo
   Serna.
 
diff --git a/Modules/_pickle.c b/Modules/_pickle.c
index 822d03c49af..06bce1e6e33 100644
--- a/Modules/_pickle.c
+++ b/Modules/_pickle.c
@@ -6338,8 +6338,10 @@ PyInit__pickle(void)
     if (m == NULL)
         return NULL;
 
+    Py_INCREF(&Pickler_Type);
     if (PyModule_AddObject(m, "Pickler", (PyObject *)&Pickler_Type) < 0)
         return NULL;
+    Py_INCREF(&Unpickler_Type);
     if (PyModule_AddObject(m, "Unpickler", (PyObject *)&Unpickler_Type) < 0)
         return NULL;