diff --git a/RTCP/Storage/include/Storage/OutputThread.h b/RTCP/Storage/include/Storage/OutputThread.h
index 4650197bb2ae5df8e6964b4cda9c46f615ff50a3..c5c45a78f3b03fc3f18831277c231a9424d7d096 100644
--- a/RTCP/Storage/include/Storage/OutputThread.h
+++ b/RTCP/Storage/include/Storage/OutputThread.h
@@ -69,6 +69,7 @@ class OutputThread
     Queue<SmartPtr<StreamableData> > &itsFreeQueue, &itsReceiveQueue;
 
     unsigned		 	     itsBlocksWritten, itsBlocksDropped;
+    unsigned           itsNrExpectedBlocks;
     unsigned			     itsNextSequenceNumber;
     std::vector<unsigned>	     itsSequenceNumbers;
     SmartPtr<FileStream>	     itsSequenceNumbersFile;
diff --git a/RTCP/Storage/src/MSWriterDAL.cc b/RTCP/Storage/src/MSWriterDAL.cc
index 9f848963593cfb4e150cb60a64d38657f7b7a6ed..029c2908afd0525ae04ba1e92c0bd53f30710c59 100644
--- a/RTCP/Storage/src/MSWriterDAL.cc
+++ b/RTCP/Storage/src/MSWriterDAL.cc
@@ -118,7 +118,7 @@ namespace LOFAR
 
       itsTransposeLogic.decompose( fileno, sapNr, beamNr, stokesNr, partNr );
 
-      unsigned nrBlocks = floor((parset.stopTime() - parset.startTime()) / parset.CNintegrationTime());
+      unsigned nrBlocks = parset.nrBeamFormedBlocks();
       unsigned nrSubbands = itsInfo.subbands.size();
       const vector<unsigned> &subbandIndices = itsInfo.subbands;
       const vector<unsigned> allSubbands = parset.subbandList();