diff --git a/payload_generator/cow_size_estimator.cc b/payload_generator/cow_size_estimator.cc
index 0578ada..36d6526 100644
--- a/payload_generator/cow_size_estimator.cc
+++ b/payload_generator/cow_size_estimator.cc
@@ -26,6 +26,7 @@
 #include "update_engine/common/cow_operation_convert.h"
 #include "update_engine/common/utils.h"
 #include "update_engine/update_metadata.pb.h"
+#include "update_engine/payload_consumer/vabc_partition_writer.h"
 
 namespace chromeos_update_engine {
 using android::snapshot::CowWriter;
@@ -162,6 +163,7 @@
     // emits 1 label for every op.
     cow_writer->AddLabel(2);
   }
+  VABCPartitionWriter::WriteMergeSequence(merge_operations, cow_writer);
   // TODO(zhangkelvin) Take FEC extents into account once VABC stabilizes
   return true;
 }