diff --git a/reco/tasks/CbmSourceTs.cxx b/reco/tasks/CbmSourceTs.cxx
index 17fc083a9965dad5e32124397e2967f1bc5efed6..afbcfb44f10db5f91cc6e4fb9ef55509a7734f53 100644
--- a/reco/tasks/CbmSourceTs.cxx
+++ b/reco/tasks/CbmSourceTs.cxx
@@ -61,6 +61,7 @@ Int_t CbmSourceTs::ReadEvent(UInt_t)
   std::cout << std::endl;
   if (fNumCalls == 0) LOG(info) << "SourceTs: Init call to ReadEvent";
   else {
+    fFlesTs = nullptr;
     fFlesTs = fFlesSource->get();
     if (!fFlesTs) {
       LOG(info) << "SourceTs: End of archive reached; stopping run.";