diff --git a/m-mutex.h b/m-mutex.h
index dd619662..f39e1388 100644
--- a/m-mutex.h
+++ b/m-mutex.h
@@ -204,6 +204,7 @@ static inline void m_thread_join(m_thread_t t)
 {
   DWORD dwWaitResult = WaitForSingleObject(*t, INFINITE);
   assert (dwWaitResult == WAIT_OBJECT_0);
+  CloseHandle(*t);
 }