diff --git a/system/mp/mpcomm.cpp b/system/mp/mpcomm.cpp
index aa69fc8cfa4..0aa74dd2ee7 100644
--- a/system/mp/mpcomm.cpp
+++ b/system/mp/mpcomm.cpp
@@ -221,7 +221,6 @@ struct MultiPacketHeader
 
 class DECL_EXCEPTION CMPException: public IMP_Exception, public CInterface
 {
-    StringAttr msg;
 public:
     IMPLEMENT_IINTERFACE;
 
@@ -254,6 +253,7 @@ class DECL_EXCEPTION CMPException: public IMP_Exception, public CInterface
 private:
     MessagePassingError error;
     SocketEndpoint endpoint;
+    StringAttr msg;
 };