classes with virtual methods need a virtual destructor
diff --git a/aos/common/util/thread.h b/aos/common/util/thread.h
index 10867ec..ab6f09c 100644
--- a/aos/common/util/thread.h
+++ b/aos/common/util/thread.h
@@ -12,7 +12,7 @@
 class Thread {
  public:
   Thread();
-  ~Thread();
+  virtual ~Thread();
 
   // Actually creates the thread.
   void Start();