diff --git a/RTCP/Cobalt/OutputProc/src/MSWriterFile.cc b/RTCP/Cobalt/OutputProc/src/MSWriterFile.cc
index 18ed73cba384c466ee1e2411af6b24f6699c2e61..f509abc2b0bb175767096fc95b2cd6429cc9ca5f 100644
--- a/RTCP/Cobalt/OutputProc/src/MSWriterFile.cc
+++ b/RTCP/Cobalt/OutputProc/src/MSWriterFile.cc
@@ -45,7 +45,7 @@ namespace LOFAR
 
     void MSWriterFile::write(StreamableData *data)
     {
-      data->write(&itsFile, true, FastFileStream::alignment);
+      data->write(&itsFile, true, 512);
     }
 
 
diff --git a/RTCP/Cobalt/OutputProc/src/MSWriterFile.h b/RTCP/Cobalt/OutputProc/src/MSWriterFile.h
index c2ed7f72aa8e78ef8d17a92a483b40d6af2012f0..08a37224bb6cc363938a88201020a2c5d3c301be 100644
--- a/RTCP/Cobalt/OutputProc/src/MSWriterFile.h
+++ b/RTCP/Cobalt/OutputProc/src/MSWriterFile.h
@@ -25,7 +25,7 @@
 
 #include <CoInterface/StreamableData.h>
 #include "MSWriter.h"
-#include "FastFileStream.h"
+#include <Stream/FileStream.h>
 
 namespace LOFAR
 {
@@ -44,7 +44,7 @@ namespace LOFAR
       virtual size_t getDataSize();
 
     protected:
-      FastFileStream itsFile;
+      FileStream itsFile;
     };