diff --git a/src/win32/thread.cpp b/src/win32/thread.cpp
index 8d8e3e2b..22ddf7d8 100644
--- a/src/win32/thread.cpp
+++ b/src/win32/thread.cpp
@@ -279,12 +279,12 @@ namespace boost
                 interruption_enabled=false;
 #endif
             }
-//            ~externally_launched_thread() {
-//              BOOST_ASSERT(notify.empty());
-//              notify.clear();
-//              BOOST_ASSERT(async_states_.empty());
-//              async_states_.clear();
-//            }
+            ~externally_launched_thread() {
+              BOOST_ASSERT(notify.empty());
+              notify.clear();
+              BOOST_ASSERT(async_states_.empty());
+              async_states_.clear();
+            }
 
             void run()
             {}