diff --git a/contrib/pg_upgrade/server.c b/contrib/pg_upgrade/server.c
new file mode 100644
index a9f9d85..e64d0c4
*** a/contrib/pg_upgrade/server.c
--- b/contrib/pg_upgrade/server.c
*************** start_postmaster(ClusterInfo *cluster)
*** 207,216 ****
  	 * vacuums can still happen, so we set autovacuum_freeze_max_age to its
  	 * maximum.  We assume all datfrozenxid and relfrozen values are less than
  	 * a gap of 2000000000 from the current xid counter, so autovacuum will
! 	 * not touch them.
  	 */
  	snprintf(cmd, sizeof(cmd),
! 			 "\"%s/pg_ctl\" -w -l \"%s\" -D \"%s\" -o \"-p %d %s %s%s\" start",
  		  cluster->bindir, SERVER_LOG_FILE, cluster->pgconfig, cluster->port,
  			 (cluster->controldata.cat_ver >=
  			  BINARY_UPGRADE_SERVER_FLAG_CAT_VER) ? "-b" :
--- 207,217 ----
  	 * vacuums can still happen, so we set autovacuum_freeze_max_age to its
  	 * maximum.  We assume all datfrozenxid and relfrozen values are less than
  	 * a gap of 2000000000 from the current xid counter, so autovacuum will
! 	 * not touch them.  synchronous_commit=off improves object creation speed.
  	 */
  	snprintf(cmd, sizeof(cmd),
! 			 "\"%s/pg_ctl\" -w -l \"%s\" -D \"%s\" -o \"-p %d "
! 			 "-c synchronous_commit=off %s %s%s\" start",
  		  cluster->bindir, SERVER_LOG_FILE, cluster->pgconfig, cluster->port,
  			 (cluster->controldata.cat_ver >=
  			  BINARY_UPGRADE_SERVER_FLAG_CAT_VER) ? "-b" :