diff --git a/src/backend/access/heap/vacuumlazy.c b/src/backend/access/heap/vacuumlazy.c
index f12c41f..d4ffd1b 100644
--- a/src/backend/access/heap/vacuumlazy.c
+++ b/src/backend/access/heap/vacuumlazy.c
@@ -2158,11 +2158,12 @@ vacuum_indexes_leader(Relation *Irel, IndexBulkDeleteResult **stats,
 
 	for (i = 0; i < nindexes; i++)
 	{
-		bool		skip_index = (get_indstats(lps->lvshared, i) == NULL ||
-								  skip_parallel_vacuum_index(Irel[i], lps->lvshared));
+		bool		can_parallel = (get_indstats(lps->lvshared, i) == NULL ||
+									skip_parallel_vacuum_index(Irel[i],
+															   lps->lvshared));
 
 		/* Skip the indexes that can be processed by parallel workers */
-		if (!skip_index)
+		if (!can_parallel)
 			continue;
 
 		vacuum_one_index(Irel[i], &(stats[i]), lps->lvshared,
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 6526cc1..a32fe28 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -430,6 +430,7 @@ vacuum(List *relations, VacuumParams *params,
 	PG_TRY();
 	{
 		ListCell   *cur;
+		int			nworkers = params->nworkers;
 
 		in_vacuum = true;
 		VacuumCostActive = (VacuumCostDelay > 0);
@@ -446,6 +447,14 @@ vacuum(List *relations, VacuumParams *params,
 		{
 			VacuumRelation *vrel = lfirst_node(VacuumRelation, cur);
 
+			/*
+			 * Copy the number of workers.  It is possible that we might
+			 * reseted nworkers to -1 to disable parallel vacuum for temp
+			 * tables.
+			 */
+			if (nworkers != params->nworkers)
+				params->nworkers = nworkers;
+
 			if (params->options & VACOPT_VACUUM)
 			{
 				if (!vacuum_rel(vrel->oid, vrel->relation, params))