diff --git a/common/action_pipe.h b/common/action_pipe.h
index 0c98ee1..4c56812 100644
--- a/common/action_pipe.h
+++ b/common/action_pipe.h
@@ -79,6 +79,8 @@
 
  private:
   ObjectType contents_;
+  // Give unit test access
+  friend class DownloadActionTest;
 
   // The ctor is private. This is because this class should construct itself
   // via the static Bond() method.