diff --git a/contrib/postgres_fdw/postgres_fdw.c b/contrib/postgres_fdw/postgres_fdw.c
index ffe6388..7475801 100644
--- a/contrib/postgres_fdw/postgres_fdw.c
+++ b/contrib/postgres_fdw/postgres_fdw.c
@@ -3480,44 +3480,44 @@ foreign_join_ok(PlannerInfo *root, RelOptInfo *joinrel, JoinType jointype,
 	 * join is evaluated. The clauses from inner side are added to the
 	 * joinclauses, since they need to evaluated while constructing the join.
 	 *
 	 * The joining sides can not have local conditions, thus no need to test
 	 * shippability of the clauses being pulled up.
 	 */
 	switch (jointype)
 	{
 		case JOIN_INNER:
 			fpinfo->remote_conds = list_concat(fpinfo->remote_conds,
-											   fpinfo_i->remote_conds);
+										  list_copy(fpinfo_i->remote_conds));
 			fpinfo->remote_conds = list_concat(fpinfo->remote_conds,
-											   fpinfo_o->remote_conds);
+										  list_copy(fpinfo_o->remote_conds));
 			break;
 
 		case JOIN_LEFT:
 			fpinfo->joinclauses = list_concat(fpinfo->joinclauses,
-											  fpinfo_i->remote_conds);
+										  list_copy(fpinfo_i->remote_conds));
 			fpinfo->remote_conds = list_concat(fpinfo->remote_conds,
-											   fpinfo_o->remote_conds);
+										  list_copy(fpinfo_o->remote_conds));
 			break;
 
 		case JOIN_RIGHT:
 			fpinfo->joinclauses = list_concat(fpinfo->joinclauses,
-											  fpinfo_o->remote_conds);
+										  list_copy(fpinfo_o->remote_conds));
 			fpinfo->remote_conds = list_concat(fpinfo->remote_conds,
-											   fpinfo_i->remote_conds);
+										  list_copy(fpinfo_i->remote_conds));
 			break;
 
 		case JOIN_FULL:
 			fpinfo->joinclauses = list_concat(fpinfo->joinclauses,
-											  fpinfo_i->remote_conds);
+										  list_copy(fpinfo_i->remote_conds));
 			fpinfo->joinclauses = list_concat(fpinfo->joinclauses,
-											  fpinfo_o->remote_conds);
+										  list_copy(fpinfo_o->remote_conds));
 			break;
 
 		default:
 			/* Should not happen, we have just check this above */
 			elog(ERROR, "unsupported join type %d", jointype);
 	}
 
 	/*
 	 * Set the string describing this join relation to be used in EXPLAIN
 	 * output of corresponding ForeignScan.