diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
new file mode 100644
index 3d2c739..b33dfd1
*** a/src/backend/commands/vacuum.c
--- b/src/backend/commands/vacuum.c
*************** vac_update_datfrozenxid(void)
*** 901,907 ****
  static void
  vac_truncate_clog(TransactionId frozenXID, MultiXactId minMulti)
  {
! 	TransactionId myXID = GetCurrentTransactionId();
  	Relation	relation;
  	HeapScanDesc scan;
  	HeapTuple	tuple;
--- 901,907 ----
  static void
  vac_truncate_clog(TransactionId frozenXID, MultiXactId minMulti)
  {
! 	TransactionId myXID = ReadNewTransactionId();
  	Relation	relation;
  	HeapScanDesc scan;
  	HeapTuple	tuple;