diff --git a/src/backend/commands/vacuumparallel.c b/src/backend/commands/vacuumparallel.c
index b07124d1467..fbbd4f5a622 100644
--- a/src/backend/commands/vacuumparallel.c
+++ b/src/backend/commands/vacuumparallel.c
@@ -47,6 +47,7 @@
 #include "storage/bufmgr.h"
 #include "storage/proc.h"
 #include "tcop/tcopprot.h"
+#include "utils/injection_point.h"
 #include "utils/lsyscache.h"
 #include "utils/rel.h"
 
@@ -1269,6 +1270,9 @@ parallel_vacuum_main(dsm_segment *seg, shm_toc *toc)
 
 	elog(DEBUG1, "starting parallel vacuum worker");
 
+	/* Used by tests to hold a worker while it is attached to its leader */
+	INJECTION_POINT("parallel-vacuum-worker-start", NULL);
+
 	shared = (PVShared *) shm_toc_lookup(toc, PARALLEL_VACUUM_KEY_SHARED, false);
 
 	/* Set debug_query_string for individual workers */
diff --git a/src/backend/storage/ipc/procarray.c b/src/backend/storage/ipc/procarray.c
index dd221018322..c03ced3ad37 100644
--- a/src/backend/storage/ipc/procarray.c
+++ b/src/backend/storage/ipc/procarray.c
@@ -3882,8 +3882,9 @@ TerminateOtherDBBackends(Oid databaseId)
 		 * Permissions checks relax the pg_terminate_backend checks in two
 		 * ways, both by omitting the !OidIsValid(proc->roleId) check:
 		 *
-		 * - Accept terminating autovacuum workers, since DROP DATABASE
-		 * without FORCE terminates them.
+		 * - Accept terminating autovacuum workers and the parallel workers
+		 * launched by them, since DROP DATABASE without FORCE terminates
+		 * them.
 		 *
 		 * - Accept terminating bgworkers.  For bgworker authors, it's
 		 * convenient to be able to recommend FORCE if a worker is blocking
@@ -3900,14 +3901,30 @@ TerminateOtherDBBackends(Oid databaseId)
 
 			if (proc != NULL)
 			{
-				if (superuser_arg(proc->roleId) && !superuser())
+				PGPROC	   *leader = proc->lockGroupLeader;
+				Oid			roleId = proc->roleId;
+
+				/*
+				 * An autovacuum worker and a bgworker with no user name
+				 * advertise no role in PGPROC and run as the bootstrap
+				 * superuser (see InitializeSessionUserIdStandalone()
+				 * callsites in postinit.c). The parallel workers they launch
+				 * inherit the same superuser and advertise it in their
+				 * PGPROC. Accept such parallel workers for terminating as
+				 * well.
+				 */
+				if (leader != NULL && leader != proc &&
+					!OidIsValid(leader->roleId))
+					roleId = leader->roleId;
+
+				if (superuser_arg(roleId) && !superuser())
 					ereport(ERROR,
 							(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
 							 errmsg("permission denied to terminate process"),
 							 errdetail("Only roles with the %s attribute may terminate processes of roles with the %s attribute.",
 									   "SUPERUSER", "SUPERUSER")));
 
-				if (!has_privs_of_role(GetUserId(), proc->roleId) &&
+				if (!has_privs_of_role(GetUserId(), roleId) &&
 					!has_privs_of_role(GetUserId(), ROLE_PG_SIGNAL_BACKEND))
 					ereport(ERROR,
 							(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
diff --git a/src/test/modules/test_autovacuum/t/001_parallel_autovacuum.pl b/src/test/modules/test_autovacuum/t/001_parallel_autovacuum.pl
index 115f92a49e4..7312ae3dd4a 100644
--- a/src/test/modules/test_autovacuum/t/001_parallel_autovacuum.pl
+++ b/src/test/modules/test_autovacuum/t/001_parallel_autovacuum.pl
@@ -254,5 +254,47 @@ $node->safe_psql('postgres',
 $node->safe_psql('postgres',
 	"SELECT injection_points_detach('autovacuum-worker-cost-balanced')");
 
+# Test 4:
+# Check that DROP DATABASE FORCE run by a non-superuser terminates both an
+# autovacuum worker and its parallel workers.
+$node->safe_psql(
+	'postgres', qq{
+	DROP TABLE test_autovac;
+	CREATE ROLE regress_dbowner LOGIN IN ROLE pg_signal_backend;
+	ALTER DATABASE regress_db2 OWNER TO regress_dbowner;
+	SELECT injection_points_attach('parallel-vacuum-worker-start', 'wait');
+});
+
+$node->safe_psql(
+	'regress_db2', qq{
+	CREATE TABLE tbl_fddb (a int, b int)
+	  WITH (autovacuum_parallel_workers = 1, autovacuum_vacuum_threshold = 1);
+	INSERT INTO tbl_fddb SELECT g, g FROM generate_series(1, 100) g;
+	CREATE INDEX tbl_fddb_a ON tbl_fddb (a);
+	CREATE INDEX tbl_fddb_b ON tbl_fddb (b);
+	DELETE FROM tbl_fddb;
+});
+
+$node->wait_for_event('parallel worker', 'parallel-vacuum-worker-start');
+
+$log_offset = -s $node->logfile;
+
+my $psql_err = '';
+$node->psql(
+	'postgres',
+	'DROP DATABASE regress_db2 WITH (FORCE)',
+	connstr => $node->connstr('postgres') . ' user=regress_dbowner',
+	stderr => \$psql_err);
+is($psql_err, '', 'no error from DROP DATABASE FORCE');
+
+ok( $node->log_contains(
+		qr/FATAL: .*terminating background worker "parallel worker" due to administrator command/,
+		$log_offset),
+	'DROP DATABASE FORCE terminates parallel autovacuum workers');
+
+# No wakeup, the held worker is already gone.
+$node->safe_psql('postgres',
+	"SELECT injection_points_detach('parallel-vacuum-worker-start')");
+
 $node->stop;
 done_testing();