diff --git a/src/backend/optimizer/path/costsize.c b/src/backend/optimizer/path/costsize.c
index c5f6593..daaefdc 100644
--- a/src/backend/optimizer/path/costsize.c
+++ b/src/backend/optimizer/path/costsize.c
@@ -122,6 +122,7 @@ Cost		disable_cost = 1.0e10;
 int			max_parallel_workers_per_gather = 2;
 
 bool		enable_seqscan = true;
+bool		enable_singleseqscan = true;
 bool		enable_indexscan = true;
 bool		enable_indexonlyscan = true;
 bool		enable_bitmapscan = true;
@@ -231,6 +232,9 @@ cost_seqscan(Path *path, PlannerInfo *root,
 	if (!enable_seqscan)
 		startup_cost += disable_cost;
 
+	if (!enable_singleseqscan && path->parallel_workers==0)
+		startup_cost += disable_cost;
+
 	/* fetch estimated page cost for tablespace containing table */
 	get_tablespace_page_costs(baserel->reltablespace,
 							  NULL,
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index ba74bf9..df22e08 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -898,6 +898,16 @@ static struct config_bool ConfigureNamesBool[] =
 		NULL, NULL, NULL
 	},
 	{
+		{"enable_singleseqscan", PGC_USERSET, QUERY_TUNING_METHOD,
+			gettext_noop("Enables the planner's use of non-parallel sequential-scan plans."),
+			NULL,
+			GUC_EXPLAIN
+		},
+		&enable_singleseqscan,
+		true,
+		NULL, NULL, NULL
+	},
+	{
 		{"enable_indexscan", PGC_USERSET, QUERY_TUNING_METHOD,
 			gettext_noop("Enables the planner's use of index-scan plans."),
 			NULL,
diff --git a/src/include/optimizer/cost.h b/src/include/optimizer/cost.h
index b3d0b4f..79ce31d 100644
--- a/src/include/optimizer/cost.h
+++ b/src/include/optimizer/cost.h
@@ -48,6 +48,7 @@ typedef enum
 extern PGDLLIMPORT Cost disable_cost;
 extern PGDLLIMPORT int max_parallel_workers_per_gather;
 extern PGDLLIMPORT bool enable_seqscan;
+extern PGDLLIMPORT bool enable_singleseqscan;
 extern PGDLLIMPORT bool enable_indexscan;
 extern PGDLLIMPORT bool enable_indexonlyscan;
 extern PGDLLIMPORT bool enable_bitmapscan;
diff --git a/src/test/regress/expected/sysviews.out b/src/test/regress/expected/sysviews.out
index a1c90eb..8389cf9 100644
--- a/src/test/regress/expected/sysviews.out
+++ b/src/test/regress/expected/sysviews.out
@@ -87,9 +87,10 @@ select name, setting from pg_settings where name like 'enable%';
  enable_partitionwise_aggregate | off
  enable_partitionwise_join      | off
  enable_seqscan                 | on
+ enable_singleseqscan           | on
  enable_sort                    | on
  enable_tidscan                 | on
-(17 rows)
+(18 rows)
 
 -- Test that the pg_timezone_names and pg_timezone_abbrevs views are
 -- more-or-less working.  We can't test their contents in any great detail