diff --git a/TestBeam/TBCnv/src/TBByteStreamCnvTool.cxx b/TestBeam/TBCnv/src/TBByteStreamCnvTool.cxx
index d0e45b617295d4b27370cd598d25202247bdd005..e7053138464e348362650e1390bc011238c5a9bb 100644
--- a/TestBeam/TBCnv/src/TBByteStreamCnvTool.cxx
+++ b/TestBeam/TBCnv/src/TBByteStreamCnvTool.cxx
@@ -230,7 +230,7 @@ StatusCode TBByteStreamCnvTool::BuildRODBlock(std::vector<uint32_t> *theRodBlock
   StatusCode sc;
 
   // TBTDCRaw part of the block : 
-  const TBTDC* tbtdc;
+  const TBTDC* tbtdc = nullptr;
   std::string tbtdc_Key("TBTDC");
   sc=evtStore()->retrieve(tbtdc,tbtdc_Key);
   if (sc!=StatusCode::SUCCESS)