diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index b316543c224c..48c588f68b09 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,9 @@
+2005-10-17  Jonathan Wakely  <redi@gcc.gnu.org>
+
+	PR libstdc++/24244
+	* include/tr1/boost_shared_ptr.h (_Sp_counted_base::_Sp_counted_base()):
+	When __GTHREAD_MUTEX_INIT is defined, initialize the mutex.
+
 2005-10-15  Paolo Carlini  <pcarlini@suse.de>
 
 	* include/tr1/functional: Add missing #pragma GCC system_header.
diff --git a/libstdc++-v3/include/tr1/boost_shared_ptr.h b/libstdc++-v3/include/tr1/boost_shared_ptr.h
index a998fed2d714..8f95ead7dd5f 100644
--- a/libstdc++-v3/include/tr1/boost_shared_ptr.h
+++ b/libstdc++-v3/include/tr1/boost_shared_ptr.h
@@ -101,7 +101,14 @@ public:
 
   _Sp_counted_base()
   : _M_use_count(1), _M_weak_count(1)
-  { }
+  {
+    // For the case of __GTHREAD_MUTEX_INIT we haven't initialised
+    // the mutex yet, so do it now.
+#if defined(__GTHREADS) && defined(__GTHREAD_MUTEX_INIT)
+    __gthread_mutex_t __tmp = __GTHREAD_MUTEX_INIT;
+    _M_mutex = __tmp;
+#endif
+  }
 
   virtual
   ~_Sp_counted_base() // nothrow