diff --git a/src/systhread.c b/src/systhread.c
index 968620bcd1c..666641c24da 100644
--- a/src/systhread.c
+++ b/src/systhread.c
@@ -78,67 +78,6 @@ sys_cond_destroy (sys_cond_t *cond)
   pthread_cond_destroy (cond);
 }
 
-void
-lisp_mutex_init (lisp_mutex_t *mutex)
-{
-  mutex->owner = NULL;
-  mutex->count = 0;
-  /* A lisp "mutex" is really a condition variable.  */
-  pthread_cond_init (&mutex->condition, NULL);
-}
-
-void
-lisp_mutex_lock (lisp_mutex_t *mutex)
-{
-  struct thread_state *self;
-
-  if (mutex->owner == NULL)
-    {
-      mutex->owner = current_thread;
-      mutex->count = 1;
-      return;
-    }
-  if (mutex->owner == current_thread)
-    {
-      ++mutex->count;
-      return;
-    }
-
-  self = current_thread;
-  self->wait_condvar = &mutex->condition;
-  while (mutex->owner != NULL && EQ (self->error_symbol, Qnil))
-    pthread_cond_wait (&mutex->condition, &global_lock);
-  self->wait_condvar = NULL;
-
-  post_acquire_global_lock (self);
-
-  mutex->owner = self;
-  mutex->count = 1;
-}
-
-void
-lisp_mutex_unlock (lisp_mutex_t *mutex)
-{
-  struct thread_state *self = current_thread;
-
-  if (mutex->owner != current_thread)
-    error ("blah");
-
-  if (--mutex->count > 0)
-    return;
-
-  mutex->owner = NULL;
-  pthread_cond_broadcast (&mutex->condition);
-
-  post_acquire_global_lock (self);
-}
-
-void
-lisp_mutex_destroy (lisp_mutex_t *mutex)
-{
-  sys_cond_destroy (&mutex->condition);
-}
-
 sys_thread_t
 sys_thread_self (void)
 {
diff --git a/src/systhread.h b/src/systhread.h
index bf9358c21c6..790b385b7ff 100644
--- a/src/systhread.h
+++ b/src/systhread.h
@@ -23,19 +23,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include <pthread.h>
 
-/* A mutex in lisp is represented by a pthread condition variable.
-   The pthread mutex associated with this condition variable is the
-   global lock.
-
-   Using a condition variable lets us implement interruptibility for
-   lisp mutexes.  */
-typedef struct
-{
-  struct thread_state *owner;
-  unsigned int count;
-  pthread_cond_t condition;
-} lisp_mutex_t;
-
 /* A system mutex is just a pthread mutex.  This is only used for the
    GIL.  */
 typedef pthread_mutex_t sys_mutex_t;
@@ -64,11 +51,6 @@ extern void sys_cond_signal (sys_cond_t *);
 extern void sys_cond_broadcast (sys_cond_t *);
 extern void sys_cond_destroy (sys_cond_t *);
 
-extern void lisp_mutex_init (lisp_mutex_t *);
-extern void lisp_mutex_lock (lisp_mutex_t *);
-extern void lisp_mutex_unlock (lisp_mutex_t *);
-extern void lisp_mutex_destroy (lisp_mutex_t *);
-
 extern sys_thread_t sys_thread_self (void);
 extern int sys_thread_equal (sys_thread_t, sys_thread_t);
 
diff --git a/src/thread.c b/src/thread.c
index e8e43c5e402..9c39b84eb50 100644
--- a/src/thread.c
+++ b/src/thread.c
@@ -30,12 +30,119 @@ struct thread_state *current_thread = &primary_thread;
 
 static struct thread_state *all_threads = &primary_thread;
 
-sys_mutex_t global_lock;
+static sys_mutex_t global_lock;
 
 Lisp_Object Qthreadp, Qmutexp;
 
 
 
+static void
+release_global_lock (void)
+{
+  sys_mutex_unlock (&global_lock);
+}
+
+/* You must call this after acquiring the global lock.
+   acquire_global_lock does it for you.  */
+static void
+post_acquire_global_lock (struct thread_state *self)
+{
+  Lisp_Object buffer;
+
+  if (self != current_thread)
+    {
+      unbind_for_thread_switch ();
+      current_thread = self;
+      rebind_for_thread_switch ();
+    }
+
+  /* We need special handling to re-set the buffer.  */
+  XSETBUFFER (buffer, self->m_current_buffer);
+  self->m_current_buffer = 0;
+  set_buffer_internal (XBUFFER (buffer));
+
+  if (!EQ (current_thread->error_symbol, Qnil))
+    {
+      Lisp_Object sym = current_thread->error_symbol;
+      Lisp_Object data = current_thread->error_data;
+
+      current_thread->error_symbol = Qnil;
+      current_thread->error_data = Qnil;
+      Fsignal (sym, data);
+    }
+}
+
+static void
+acquire_global_lock (struct thread_state *self)
+{
+  sys_mutex_lock (&global_lock);
+  post_acquire_global_lock (self);
+}
+
+
+
+static void
+lisp_mutex_init (lisp_mutex_t *mutex)
+{
+  mutex->owner = NULL;
+  mutex->count = 0;
+  sys_cond_init (&mutex->condition);
+}
+
+static void
+lisp_mutex_lock (lisp_mutex_t *mutex)
+{
+  struct thread_state *self;
+
+  if (mutex->owner == NULL)
+    {
+      mutex->owner = current_thread;
+      mutex->count = 1;
+      return;
+    }
+  if (mutex->owner == current_thread)
+    {
+      ++mutex->count;
+      return;
+    }
+
+  self = current_thread;
+  self->wait_condvar = &mutex->condition;
+  while (mutex->owner != NULL && EQ (self->error_symbol, Qnil))
+    sys_cond_wait (&mutex->condition, &global_lock);
+  self->wait_condvar = NULL;
+
+  post_acquire_global_lock (self);
+
+  mutex->owner = self;
+  mutex->count = 1;
+}
+
+static void
+lisp_mutex_unlock (lisp_mutex_t *mutex)
+{
+  struct thread_state *self = current_thread;
+
+  if (mutex->owner != current_thread)
+    error ("blah");
+
+  if (--mutex->count > 0)
+    return;
+
+  mutex->owner = NULL;
+  sys_cond_broadcast (&mutex->condition);
+
+  post_acquire_global_lock (self);
+}
+
+static void
+lisp_mutex_destroy (lisp_mutex_t *mutex)
+{
+  sys_cond_destroy (&mutex->condition);
+}
+
+
+
 DEFUN ("make-mutex", Fmake_mutex, Smake_mutex, 0, 1, 0,
        doc: /* Create a mutex.
 A mutex provides a synchronization point for threads.
@@ -146,51 +253,6 @@ finalize_one_mutex (struct Lisp_Mutex *mutex)
 
 
 
-static void
-release_global_lock (void)
-{
-  sys_mutex_unlock (&global_lock);
-}
-
-/* You must call this after acquiring the global lock.
-   acquire_global_lock does it for you.  */
-void
-post_acquire_global_lock (struct thread_state *self)
-{
-  Lisp_Object buffer;
-
-  if (self != current_thread)
-    {
-      unbind_for_thread_switch ();
-      current_thread = self;
-      rebind_for_thread_switch ();
-    }
-
-  /* We need special handling to re-set the buffer.  */
-  XSETBUFFER (buffer, self->m_current_buffer);
-  self->m_current_buffer = 0;
-  set_buffer_internal (XBUFFER (buffer));
-
-  if (!EQ (current_thread->error_symbol, Qnil))
-    {
-      Lisp_Object sym = current_thread->error_symbol;
-      Lisp_Object data = current_thread->error_data;
-
-      current_thread->error_symbol = Qnil;
-      current_thread->error_data = Qnil;
-      Fsignal (sym, data);
-    }
-}
-
-static void
-acquire_global_lock (struct thread_state *self)
-{
-  sys_mutex_lock (&global_lock);
-  post_acquire_global_lock (self);
-}
-
-
-
 struct select_args
 {
   select_func *func;
diff --git a/src/thread.h b/src/thread.h
index 9db3c795653..32ef48f63ff 100644
--- a/src/thread.h
+++ b/src/thread.h
@@ -187,6 +187,19 @@ struct thread_state
   struct thread_state *next_thread;
 };
 
+/* A mutex in lisp is represented by a pthread condition variable.
+   The system mutex associated with this condition variable is the
+   global lock.
+
+   Using a condition variable lets us implement interruptibility for
+   lisp mutexes.  */
+typedef struct
+{
+  struct thread_state *owner;
+  unsigned int count;
+  sys_cond_t condition;
+} lisp_mutex_t;
+
 struct Lisp_Mutex
 {
   struct vectorlike_header header;
@@ -198,9 +211,6 @@ struct Lisp_Mutex
 
 extern struct thread_state *current_thread;
 
-extern sys_mutex_t global_lock;
-extern void post_acquire_global_lock (struct thread_state *);
-
 extern void unmark_threads (void);
 extern void finalize_one_thread (struct thread_state *state);
 extern void finalize_one_mutex (struct Lisp_Mutex *);