*** a/src/backend/optimizer/plan/planner.c
--- b/src/backend/optimizer/plan/planner.c
***************
*** 1989,1995 **** grouping_planner(PlannerInfo *root, bool inheritance_update,
  		{
  			scanjoin_target = make_group_input_target(root, final_target);
  			scanjoin_target_parallel_safe =
! 				is_parallel_safe(root, (Node *) grouping_target->exprs);
  		}
  		else
  		{
--- 1989,1995 ----
  		{
  			scanjoin_target = make_group_input_target(root, final_target);
  			scanjoin_target_parallel_safe =
! 				is_parallel_safe(root, (Node *) scanjoin_target->exprs);
  		}
  		else
  		{