diff --git a/error.h b/error.h
index bee2465..3c01047 100644
--- a/error.h
+++ b/error.h
@@ -51,6 +51,8 @@
 
   void Reset();
 
+  void CopyFrom(const Error &error);
+
   // Sets the DBus |error| and returns true if Error represents failure.
   // Leaves |error| unchanged, and returns false, otherwise.
   bool ToDBusError(::DBus::Error *error) const;