diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 2ca72ea84fa3..7d1788032804 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,8 @@
+2009-06-16  Jonathan Wakely  <jwakely.gcc@gmail.com>
+
+	* include/std/thread (~thread(), operator=(thread&&)): Call terminate
+	if joinable.
+
 2009-06-15  Tom Tromey  <tromey@redhat.com>
 
 	* python/libstdcxx/v6/printers.py (StdMapPrinter.__init__): Don't
diff --git a/libstdc++-v3/include/std/thread b/libstdc++-v3/include/std/thread
index fbdfe2ee53fc..bf282cc03658 100644
--- a/libstdc++-v3/include/std/thread
+++ b/libstdc++-v3/include/std/thread
@@ -135,7 +135,7 @@ namespace std
     ~thread()
     {
       if (joinable())
-	detach();
+	std::terminate();
     }
 
     thread& operator=(const thread&) = delete;
@@ -143,7 +143,7 @@ namespace std
     thread& operator=(thread&& __t)
     {
       if (joinable())
-	detach();
+	std::terminate();
       swap(__t);
       return *this;
     }