diff --git a/RTCP/Cobalt/CoInterface/src/LTAFeedback.h b/RTCP/Cobalt/CoInterface/src/LTAFeedback.h
index 83521e7f152b906a88ec536a67505129d61b90c8..e10c9d01dd4735bfe8c13fd3c1800dab62edd0fe 100644
--- a/RTCP/Cobalt/CoInterface/src/LTAFeedback.h
+++ b/RTCP/Cobalt/CoInterface/src/LTAFeedback.h
@@ -63,8 +63,8 @@ namespace LOFAR
       static const int major_version = 3;
       static const int minor_version = 1;
       static const int patch_number = 0;
-      static const std::string feedback_version(boost::str(boost::format("%02d.%02d.%02d") %
-                                            major_version % minor_version % patch_number));
+      static const std::string & feedback_version = (boost::format("%02d.%02d.%02d") %
+                                            major_version % minor_version % patch_number).str();
 
     private:
       const ObservationSettings settings;