diff --git a/Include/Python.h b/Include/Python.h
--- a/Include/Python.h
+++ b/Include/Python.h
@@ -151,11 +151,6 @@ PyAPI_FUNC(PyObject*) _Py_Mangle(PyObjec
 #define Py_file_input 257
 #define Py_eval_input 258
 
-#ifdef HAVE_PTH
-/* GNU pth user-space thread support */
-#include <pth.h>
-#endif
-
 /* Define macros for inline documentation. */
 #define PyDoc_VAR(name) static char name[]
 #define PyDoc_STRVAR(name,str) PyDoc_VAR(name) = PyDoc_STR(str)
diff --git a/PC/pyconfig.h b/PC/pyconfig.h
--- a/PC/pyconfig.h
+++ b/PC/pyconfig.h
@@ -711,9 +711,6 @@ Py_NO_ENABLE_SHARED to find out.  Also s
 /* Define if you have the <sys/utsname.h> header file.  */
 /* #define HAVE_SYS_UTSNAME_H 1 */
 
-/* Define if you have the <thread.h> header file.  */
-/* #undef HAVE_THREAD_H */
-
 /* Define if you have the <unistd.h> header file.  */
 /* #define HAVE_UNISTD_H 1 */
 
diff --git a/Python/thread.c b/Python/thread.c
--- a/Python/thread.c
+++ b/Python/thread.c
@@ -27,18 +27,6 @@
 
 #ifndef _POSIX_THREADS
 
-#ifdef __sgi
-#define SGI_THREADS
-#endif
-
-#ifdef HAVE_THREAD_H
-#define SOLARIS_THREADS
-#endif
-
-#if defined(sun) && !defined(SOLARIS_THREADS)
-#define SUN_LWP
-#endif
-
 /* Check if we're running on HP-UX and _SC_THREADS is defined. If so, then
    enough of the Posix threads package is implemented to support python
    threads.
@@ -94,35 +82,10 @@ PyThread_init_thread(void)
    or the size specified by the THREAD_STACK_SIZE macro. */
 static size_t _pythread_stacksize = 0;
 
-#ifdef SGI_THREADS
-#error SGI Irix threads are now unsupported, and code will be removed in 3.3.
-#include "thread_sgi.h"
-#endif
-
-#ifdef SOLARIS_THREADS
-#include "thread_solaris.h"
-#endif
-
-#ifdef SUN_LWP
-#error SunOS lightweight processes are now unsupported, and code will be removed in 3.3.
-#include "thread_lwp.h"
-#endif
-
-#ifdef HAVE_PTH
-#error GNU pth threads are now unsupported, and code will be removed in 3.3.
-#include "thread_pth.h"
-#undef _POSIX_THREADS
-#endif
-
 #ifdef _POSIX_THREADS
 #include "thread_pthread.h"
 #endif
 
-#ifdef C_THREADS
-#error Mach C Threads are now unsupported, and code will be removed in 3.3.
-#include "thread_cthread.h"
-#endif
-
 #ifdef NT_THREADS
 #include "thread_nt.h"
 #endif
@@ -131,10 +94,6 @@ static size_t _pythread_stacksize = 0;
 #include "thread_os2.h"
 #endif
 
-#ifdef PLAN9_THREADS
-#include "thread_plan9.h"
-#endif
-
 /*
 #ifdef FOOBAR_THREADS
 #include "thread_foobar.h"
diff --git a/Python/thread_cthread.h b/Python/thread_cthread.h
deleted file mode 100644
--- a/Python/thread_cthread.h
+++ /dev/null
@@ -1,112 +0,0 @@
-
-#ifdef MACH_C_THREADS
-#include <mach/cthreads.h>
-#endif
-
-#ifdef HURD_C_THREADS
-#include <cthreads.h>
-#endif
-
-/*
- * Initialization.
- */
-static void
-PyThread__init_thread(void)
-{
-#ifndef HURD_C_THREADS
-    /* Roland McGrath said this should not be used since this is
-    done while linking to threads */
-    cthread_init();
-#else
-/* do nothing */
-    ;
-#endif
-}
-
-/*
- * Thread support.
- */
-long
-PyThread_start_new_thread(void (*func)(void *), void *arg)
-{
-    int success = 0;            /* init not needed when SOLARIS_THREADS and */
-                /* C_THREADS implemented properly */
-
-    dprintf(("PyThread_start_new_thread called\n"));
-    if (!initialized)
-        PyThread_init_thread();
-    /* looks like solaris detaches the thread to never rejoin
-     * so well do it here
-     */
-    cthread_detach(cthread_fork((cthread_fn_t) func, arg));
-    return success < 0 ? -1 : 0;
-}
-
-long
-PyThread_get_thread_ident(void)
-{
-    if (!initialized)
-        PyThread_init_thread();
-    return (long) cthread_self();
-}
-
-void
-PyThread_exit_thread(void)
-{
-    dprintf(("PyThread_exit_thread called\n"));
-    if (!initialized)
-        exit(0);
-    cthread_exit(0);
-}
-
-/*
- * Lock support.
- */
-PyThread_type_lock
-PyThread_allocate_lock(void)
-{
-    mutex_t lock;
-
-    dprintf(("PyThread_allocate_lock called\n"));
-    if (!initialized)
-        PyThread_init_thread();
-
-    lock = mutex_alloc();
-    if (mutex_init(lock)) {
-        perror("mutex_init");
-        free((void *) lock);
-        lock = 0;
-    }
-    dprintf(("PyThread_allocate_lock() -> %p\n", lock));
-    return (PyThread_type_lock) lock;
-}
-
-void
-PyThread_free_lock(PyThread_type_lock lock)
-{
-    dprintf(("PyThread_free_lock(%p) called\n", lock));
-    mutex_free(lock);
-}
-
-int
-PyThread_acquire_lock(PyThread_type_lock lock, int waitflag)
-{
-    int success = FALSE;
-
-    dprintf(("PyThread_acquire_lock(%p, %d) called\n", lock, waitflag));
-    if (waitflag) {             /* blocking */
-        mutex_lock((mutex_t)lock);
-        success = TRUE;
-    } else {                    /* non blocking */
-        success = mutex_try_lock((mutex_t)lock);
-    }
-    dprintf(("PyThread_acquire_lock(%p, %d) -> %d\n", lock, waitflag, success));
-    return success;
-}
-
-void
-PyThread_release_lock(PyThread_type_lock lock)
-{
-    dprintf(("PyThread_release_lock(%p) called\n", lock));
-    mutex_unlock((mutex_t )lock);
-}
diff --git a/Python/thread_lwp.h b/Python/thread_lwp.h
deleted file mode 100644
--- a/Python/thread_lwp.h
+++ /dev/null
@@ -1,113 +0,0 @@
-
-#include <stdlib.h>
-#include <lwp/lwp.h>
-#include <lwp/stackdep.h>
-
-#define STACKSIZE       1000    /* stacksize for a thread */
-#define NSTACKS         2       /* # stacks to be put in cache initially */
-
-struct lock {
-    int lock_locked;
-    cv_t lock_condvar;
-    mon_t lock_monitor;
-};
-
-
-/*
- * Initialization.
- */
-static void PyThread__init_thread(void)
-{
-    lwp_setstkcache(STACKSIZE, NSTACKS);
-}
-
-/*
- * Thread support.
- */
-
-
-long PyThread_start_new_thread(void (*func)(void *), void *arg)
-{
-    thread_t tid;
-    int success;
-    dprintf(("PyThread_start_new_thread called\n"));
-    if (!initialized)
-        PyThread_init_thread();
-    success = lwp_create(&tid, func, MINPRIO, 0, lwp_newstk(), 1, arg);
-    return success < 0 ? -1 : 0;
-}
-
-long PyThread_get_thread_ident(void)
-{
-    thread_t tid;
-    if (!initialized)
-        PyThread_init_thread();
-    if (lwp_self(&tid) < 0)
-        return -1;
-    return tid.thread_id;
-}
-
-void PyThread_exit_thread(void)
-{
-    dprintf(("PyThread_exit_thread called\n"));
-    if (!initialized)
-        exit(0);
-    lwp_destroy(SELF);
-}
-
-/*
- * Lock support.
- */
-PyThread_type_lock PyThread_allocate_lock(void)
-{
-    struct lock *lock;
-    extern char *malloc(size_t);
-
-    dprintf(("PyThread_allocate_lock called\n"));
-    if (!initialized)
-        PyThread_init_thread();
-
-    lock = (struct lock *) malloc(sizeof(struct lock));
-    lock->lock_locked = 0;
-    (void) mon_create(&lock->lock_monitor);
-    (void) cv_create(&lock->lock_condvar, lock->lock_monitor);
-    dprintf(("PyThread_allocate_lock() -> %p\n", lock));
-    return (PyThread_type_lock) lock;
-}
-
-void PyThread_free_lock(PyThread_type_lock lock)
-{
-    dprintf(("PyThread_free_lock(%p) called\n", lock));
-    mon_destroy(((struct lock *) lock)->lock_monitor);
-    free((char *) lock);
-}
-
-int PyThread_acquire_lock(PyThread_type_lock lock, int waitflag)
-{
-    int success;
-
-    dprintf(("PyThread_acquire_lock(%p, %d) called\n", lock, waitflag));
-    success = 0;
-
-    (void) mon_enter(((struct lock *) lock)->lock_monitor);
-    if (waitflag)
-        while (((struct lock *) lock)->lock_locked)
-            cv_wait(((struct lock *) lock)->lock_condvar);
-    if (!((struct lock *) lock)->lock_locked) {
-        success = 1;
-        ((struct lock *) lock)->lock_locked = 1;
-    }
-    cv_broadcast(((struct lock *) lock)->lock_condvar);
-    mon_exit(((struct lock *) lock)->lock_monitor);
-    dprintf(("PyThread_acquire_lock(%p, %d) -> %d\n", lock, waitflag, success));
-    return success;
-}
-
-void PyThread_release_lock(PyThread_type_lock lock)
-{
-    dprintf(("PyThread_release_lock(%p) called\n", lock));
-    (void) mon_enter(((struct lock *) lock)->lock_monitor);
-    ((struct lock *) lock)->lock_locked = 0;
-    cv_broadcast(((struct lock *) lock)->lock_condvar);
-    mon_exit(((struct lock *) lock)->lock_monitor);
-}
diff --git a/Python/thread_sgi.h b/Python/thread_sgi.h
deleted file mode 100644
--- a/Python/thread_sgi.h
+++ /dev/null
@@ -1,259 +0,0 @@
-
-#include <stdlib.h>
-#include <stdio.h>
-#include <signal.h>
-#include <sys/types.h>
-#include <sys/wait.h>
-#include <sys/prctl.h>
-#include <ulocks.h>
-#include <errno.h>
-
-#define HDR_SIZE        2680    /* sizeof(ushdr_t) */
-#define MAXPROC         100     /* max # of threads that can be started */
-
-static usptr_t *shared_arena;
-static ulock_t count_lock;      /* protection for some variables */
-static ulock_t wait_lock;       /* lock used to wait for other threads */
-static int waiting_for_threads; /* protected by count_lock */
-static int nthreads;            /* protected by count_lock */
-static int exit_status;
-static int exiting;             /* we're already exiting (for maybe_exit) */
-static pid_t my_pid;            /* PID of main thread */
-static struct pidlist {
-    pid_t parent;
-    pid_t child;
-} pidlist[MAXPROC];     /* PIDs of other threads; protected by count_lock */
-static int maxpidindex;         /* # of PIDs in pidlist */
-/*
- * Initialization.
- */
-static void PyThread__init_thread(void)
-{
-#ifdef USE_DL
-    long addr, size;
-#endif /* USE_DL */
-
-
-#ifdef USE_DL
-    if ((size = usconfig(CONF_INITSIZE, 64*1024)) < 0)
-        perror("usconfig - CONF_INITSIZE (check)");
-    if (usconfig(CONF_INITSIZE, size) < 0)
-        perror("usconfig - CONF_INITSIZE (reset)");
-    addr = (long) dl_getrange(size + HDR_SIZE);
-    dprintf(("trying to use addr %p-%p for shared arena\n", addr, addr+size));
-    errno = 0;
-    if ((addr = usconfig(CONF_ATTACHADDR, addr)) < 0 && errno != 0)
-        perror("usconfig - CONF_ATTACHADDR (set)");
-#endif /* USE_DL */
-    if (usconfig(CONF_INITUSERS, 16) < 0)
-        perror("usconfig - CONF_INITUSERS");
-    my_pid = getpid();          /* so that we know which is the main thread */
-    if (usconfig(CONF_ARENATYPE, US_SHAREDONLY) < 0)
-        perror("usconfig - CONF_ARENATYPE");
-    usconfig(CONF_LOCKTYPE, US_DEBUG); /* XXX */
-#ifdef Py_DEBUG
-    if (thread_debug & 4)
-        usconfig(CONF_LOCKTYPE, US_DEBUGPLUS);
-    else if (thread_debug & 2)
-        usconfig(CONF_LOCKTYPE, US_DEBUG);
-#endif /* Py_DEBUG */
-    if ((shared_arena = usinit(tmpnam(0))) == 0)
-        perror("usinit");
-#ifdef USE_DL
-    if (usconfig(CONF_ATTACHADDR, addr) < 0) /* reset address */
-        perror("usconfig - CONF_ATTACHADDR (reset)");
-#endif /* USE_DL */
-    if ((count_lock = usnewlock(shared_arena)) == NULL)
-        perror("usnewlock (count_lock)");
-    (void) usinitlock(count_lock);
-    if ((wait_lock = usnewlock(shared_arena)) == NULL)
-        perror("usnewlock (wait_lock)");
-    dprintf(("arena start: %p, arena size: %ld\n",  shared_arena, (long) usconfig(CONF_GETSIZE, shared_arena)));
-}
-
-/*
- * Thread support.
- */
-
-static void clean_threads(void)
-{
-    int i, j;
-    pid_t mypid, pid;
-
-    /* clean up any exited threads */
-    mypid = getpid();
-    i = 0;
-    while (i < maxpidindex) {
-        if (pidlist[i].parent == mypid && (pid = pidlist[i].child) > 0) {
-            pid = waitpid(pid, 0, WNOHANG);
-            if (pid > 0) {
-                /* a thread has exited */
-                pidlist[i] = pidlist[--maxpidindex];
-                /* remove references to children of dead proc */
-                for (j = 0; j < maxpidindex; j++)
-                    if (pidlist[j].parent == pid)
-                        pidlist[j].child = -1;
-                continue; /* don't increment i */
-            }
-        }
-        i++;
-    }
-    /* clean up the list */
-    i = 0;
-    while (i < maxpidindex) {
-        if (pidlist[i].child == -1) {
-            pidlist[i] = pidlist[--maxpidindex];
-            continue; /* don't increment i */
-        }
-        i++;
-    }
-}
-
-long PyThread_start_new_thread(void (*func)(void *), void *arg)
-{
-#ifdef USE_DL
-    long addr, size;
-    static int local_initialized = 0;
-#endif /* USE_DL */
-    int success = 0;            /* init not needed when SOLARIS_THREADS and */
-                /* C_THREADS implemented properly */
-
-    dprintf(("PyThread_start_new_thread called\n"));
-    if (!initialized)
-        PyThread_init_thread();
-    switch (ussetlock(count_lock)) {
-    case 0: return 0;
-    case -1: perror("ussetlock (count_lock)");
-    }
-    if (maxpidindex >= MAXPROC)
-        success = -1;
-    else {
-#ifdef USE_DL
-        if (!local_initialized) {
-            if ((size = usconfig(CONF_INITSIZE, 64*1024)) < 0)
-                perror("usconfig - CONF_INITSIZE (check)");
-            if (usconfig(CONF_INITSIZE, size) < 0)
-                perror("usconfig - CONF_INITSIZE (reset)");
-            addr = (long) dl_getrange(size + HDR_SIZE);
-            dprintf(("trying to use addr %p-%p for sproc\n",
-                     addr, addr+size));
-            errno = 0;
-            if ((addr = usconfig(CONF_ATTACHADDR, addr)) < 0 &&
-                errno != 0)
-                perror("usconfig - CONF_ATTACHADDR (set)");
-        }
-#endif /* USE_DL */
-        clean_threads();
-        if ((success = sproc(func, PR_SALL, arg)) < 0)
-            perror("sproc");
-#ifdef USE_DL
-        if (!local_initialized) {
-            if (usconfig(CONF_ATTACHADDR, addr) < 0)
-                /* reset address */
-                perror("usconfig - CONF_ATTACHADDR (reset)");
-            local_initialized = 1;
-        }
-#endif /* USE_DL */
-        if (success >= 0) {
-            nthreads++;
-            pidlist[maxpidindex].parent = getpid();
-            pidlist[maxpidindex++].child = success;
-            dprintf(("pidlist[%d] = %d\n",
-                     maxpidindex-1, success));
-        }
-    }
-    if (usunsetlock(count_lock) < 0)
-        perror("usunsetlock (count_lock)");
-    return success;
-}
-
-long PyThread_get_thread_ident(void)
-{
-    return getpid();
-}
-
-void PyThread_exit_thread(void)
-{
-    dprintf(("PyThread_exit_thread called\n"));
-    if (!initialized)
-        exit(0);
-    if (ussetlock(count_lock) < 0)
-        perror("ussetlock (count_lock)");
-    nthreads--;
-    if (getpid() == my_pid) {
-        /* main thread; wait for other threads to exit */
-        exiting = 1;
-        waiting_for_threads = 1;
-        if (ussetlock(wait_lock) < 0)
-            perror("ussetlock (wait_lock)");
-        for (;;) {
-            if (nthreads < 0) {
-                dprintf(("really exit (%d)\n", exit_status));
-                exit(exit_status);
-            }
-            if (usunsetlock(count_lock) < 0)
-                perror("usunsetlock (count_lock)");
-            dprintf(("waiting for other threads (%d)\n", nthreads));
-            if (ussetlock(wait_lock) < 0)
-                perror("ussetlock (wait_lock)");
-            if (ussetlock(count_lock) < 0)
-                perror("ussetlock (count_lock)");
-        }
-    }
-    /* not the main thread */
-    if (waiting_for_threads) {
-        dprintf(("main thread is waiting\n"));
-        if (usunsetlock(wait_lock) < 0)
-            perror("usunsetlock (wait_lock)");
-    }
-    if (usunsetlock(count_lock) < 0)
-        perror("usunsetlock (count_lock)");
-    _exit(0);
-}
-
-/*
- * Lock support.
- */
-PyThread_type_lock PyThread_allocate_lock(void)
-{
-    ulock_t lock;
-
-    dprintf(("PyThread_allocate_lock called\n"));
-    if (!initialized)
-        PyThread_init_thread();
-
-    if ((lock = usnewlock(shared_arena)) == NULL)
-        perror("usnewlock");
-    (void) usinitlock(lock);
-    dprintf(("PyThread_allocate_lock() -> %p\n", lock));
-    return (PyThread_type_lock) lock;
-}
-
-void PyThread_free_lock(PyThread_type_lock lock)
-{
-    dprintf(("PyThread_free_lock(%p) called\n", lock));
-    usfreelock((ulock_t) lock, shared_arena);
-}
-
-int PyThread_acquire_lock(PyThread_type_lock lock, int waitflag)
-{
-    int success;
-
-    dprintf(("PyThread_acquire_lock(%p, %d) called\n", lock, waitflag));
-    errno = 0;                  /* clear it just in case */
-    if (waitflag)
-        success = ussetlock((ulock_t) lock);
-    else
-        success = uscsetlock((ulock_t) lock, 1); /* Try it once */
-    if (success < 0)
-        perror(waitflag ? "ussetlock" : "uscsetlock");
-    dprintf(("PyThread_acquire_lock(%p, %d) -> %d\n", lock, waitflag, success));
-    return success;
-}
-
-void PyThread_release_lock(PyThread_type_lock lock)
-{
-    dprintf(("PyThread_release_lock(%p) called\n", lock));
-    if (usunsetlock((ulock_t) lock) < 0)
-        perror("usunsetlock");
-}
diff --git a/Python/thread_solaris.h b/Python/thread_solaris.h
deleted file mode 100644
--- a/Python/thread_solaris.h
+++ /dev/null
@@ -1,130 +0,0 @@
-
-#include <stdlib.h>
-#include <stdio.h>
-#include <errno.h>
-#include </usr/include/thread.h>
-#undef _POSIX_THREADS
-
-
-/*
- * Initialization.
- */
-static void PyThread__init_thread(void)
-{
-}
-
-/*
- * Thread support.
- */
-struct func_arg {
-    void (*func)(void *);
-    void *arg;
-};
-
-static void *
-new_func(void *funcarg)
-{
-    void (*func)(void *);
-    void *arg;
-
-    func = ((struct func_arg *) funcarg)->func;
-    arg = ((struct func_arg *) funcarg)->arg;
-    free(funcarg);
-    (*func)(arg);
-    return 0;
-}
-
-
-long
-PyThread_start_new_thread(void (*func)(void *), void *arg)
-{
-    thread_t tid;
-    struct func_arg *funcarg;
-
-    dprintf(("PyThread_start_new_thread called\n"));
-    if (!initialized)
-        PyThread_init_thread();
-    funcarg = (struct func_arg *) malloc(sizeof(struct func_arg));
-    funcarg->func = func;
-    funcarg->arg = arg;
-    if (thr_create(0, 0, new_func, funcarg,
-                   THR_DETACHED | THR_NEW_LWP, &tid)) {
-        perror("thr_create");
-        free((void *) funcarg);
-        return -1;
-    }
-    return tid;
-}
-
-long
-PyThread_get_thread_ident(void)
-{
-    if (!initialized)
-        PyThread_init_thread();
-    return thr_self();
-}
-
-void
-PyThread_exit_thread(void)
-{
-    dprintf(("PyThread_exit_thread called\n"));
-    if (!initialized)
-        exit(0);
-    thr_exit(0);
-}
-
-/*
- * Lock support.
- */
-PyThread_type_lock
-PyThread_allocate_lock(void)
-{
-    mutex_t *lock;
-
-    dprintf(("PyThread_allocate_lock called\n"));
-    if (!initialized)
-        PyThread_init_thread();
-
-    lock = (mutex_t *) malloc(sizeof(mutex_t));
-    if (mutex_init(lock, USYNC_THREAD, 0)) {
-        perror("mutex_init");
-        free((void *) lock);
-        lock = 0;
-    }
-    dprintf(("PyThread_allocate_lock() -> %p\n", lock));
-    return (PyThread_type_lock) lock;
-}
-
-void
-PyThread_free_lock(PyThread_type_lock lock)
-{
-    dprintf(("PyThread_free_lock(%p) called\n", lock));
-    mutex_destroy((mutex_t *) lock);
-    free((void *) lock);
-}
-
-int
-PyThread_acquire_lock(PyThread_type_lock lock, int waitflag)
-{
-    int success;
-
-    dprintf(("PyThread_acquire_lock(%p, %d) called\n", lock, waitflag));
-    if (waitflag)
-        success = mutex_lock((mutex_t *) lock);
-    else
-        success = mutex_trylock((mutex_t *) lock);
-    if (success < 0)
-        perror(waitflag ? "mutex_lock" : "mutex_trylock");
-    else
-        success = !success; /* solaris does it the other way round */
-    dprintf(("PyThread_acquire_lock(%p, %d) -> %d\n", lock, waitflag, success));
-    return success;
-}
-
-void
-PyThread_release_lock(PyThread_type_lock lock)
-{
-    dprintf(("PyThread_release_lock(%p) called\n", lock));
-    if (mutex_unlock((mutex_t *) lock))
-        perror("mutex_unlock");
-}
diff --git a/configure.in b/configure.in
--- a/configure.in
+++ b/configure.in
@@ -1274,7 +1274,7 @@ AC_HEADER_STDC
 AC_CHECK_HEADERS(asm/types.h conio.h curses.h direct.h dlfcn.h errno.h \
 fcntl.h grp.h \
 ieeefp.h io.h langinfo.h libintl.h ncurses.h poll.h process.h pthread.h \
-shadow.h signal.h stdint.h stropts.h termios.h thread.h \
+shadow.h signal.h stdint.h stropts.h termios.h \
 unistd.h utime.h \
 sys/audioio.h sys/bsdtty.h sys/epoll.h sys/event.h sys/file.h sys/loadavg.h \
 sys/lock.h sys/mkdev.h sys/modem.h \
@@ -2000,7 +2000,6 @@ AC_SUBST(LDLAST)
 
 # Templates for things AC_DEFINEd more than once.
 # For a single AC_DEFINE, no template is needed.
-AH_TEMPLATE(C_THREADS,[Define if you have the Mach cthreads package])
 AH_TEMPLATE(_REENTRANT,
   [Define to force use of thread-safe errno, h_errno, and other functions])
 AH_TEMPLATE(WITH_THREAD,
@@ -2082,17 +2081,6 @@ yes
     AC_MSG_RESULT($unistd_defines_pthreads)
 
     AC_DEFINE(_REENTRANT)
-    AC_CHECK_HEADER(cthreads.h, [AC_DEFINE(WITH_THREAD)
-    AC_DEFINE(C_THREADS)
-    AC_DEFINE(HURD_C_THREADS, 1,
-    [Define if you are using Mach cthreads directly under /include])
-    LIBS="$LIBS -lthreads"
-    THREADOBJ="Python/thread.o"],[
-    AC_CHECK_HEADER(mach/cthreads.h, [AC_DEFINE(WITH_THREAD)
-    AC_DEFINE(C_THREADS)
-    AC_DEFINE(MACH_C_THREADS, 1,
-    [Define if you are using Mach cthreads under mach /])
-    THREADOBJ="Python/thread.o"],[
     # Just looking for pthread_create in libpthread is not enough:
     # on HP/UX, pthread.h renames pthread_create to a different symbol name.
     # So we really have to include pthread.h, and then link.
diff --git a/pyconfig.h.in b/pyconfig.h.in
--- a/pyconfig.h.in
+++ b/pyconfig.h.in
@@ -12,9 +12,6 @@
    support for AIX C++ shared extension modules. */
 #undef AIX_GENUINE_CPLUSPLUS
 
-/* Define if you have the Mach cthreads package */
-#undef C_THREADS
-
 /* Define if C doubles are 64-bit IEEE 754 binary format, stored in ARM
    mixed-endian order (byte order 45670123) */
 #undef DOUBLE_IS_ARM_MIXED_ENDIAN_IEEE754
@@ -918,9 +915,6 @@
 /* Define to 1 if you have the `tgamma' function. */
 #undef HAVE_TGAMMA
 
-/* Define to 1 if you have the <thread.h> header file. */
-#undef HAVE_THREAD_H
-
 /* Define to 1 if you have the `timegm' function. */
 #undef HAVE_TIMEGM
 
@@ -1019,15 +1013,9 @@
 /* Define to 1 if you have the `_getpty' function. */
 #undef HAVE__GETPTY
 
-/* Define if you are using Mach cthreads directly under /include */
-#undef HURD_C_THREADS
-
 /* Define if log1p(-0.) is 0. rather than -0. */
 #undef LOG1P_DROPS_ZERO_SIGN
 
-/* Define if you are using Mach cthreads under mach / */
-#undef MACH_C_THREADS
-
 /* Define to 1 if `major', `minor', and `makedev' are declared in <mkdev.h>.
    */
 #undef MAJOR_IN_MKDEV