diff --git a/src/backend/optimizer/plan/setrefs.c b/src/backend/optimizer/plan/setrefs.c
index f66de15db31..e5786455704 100644
--- a/src/backend/optimizer/plan/setrefs.c
+++ b/src/backend/optimizer/plan/setrefs.c
@@ -1405,6 +1405,12 @@ set_append_references(PlannerInfo *root,
 				PartitionedRelPruneInfo *pinfo = lfirst(l2);
 
 				pinfo->rtindex += rtoffset;
+				pinfo->initial_pruning_steps =
+					fix_scan_list(root, pinfo->initial_pruning_steps,
+								  rtoffset);
+				pinfo->exec_pruning_steps =
+					fix_scan_list(root, pinfo->exec_pruning_steps,
+								  rtoffset);
 			}
 		}
 	}
@@ -1477,6 +1483,12 @@ set_mergeappend_references(PlannerInfo *root,
 				PartitionedRelPruneInfo *pinfo = lfirst(l2);
 
 				pinfo->rtindex += rtoffset;
+				pinfo->initial_pruning_steps =
+					fix_scan_list(root, pinfo->initial_pruning_steps,
+								  rtoffset);
+				pinfo->exec_pruning_steps =
+					fix_scan_list(root, pinfo->exec_pruning_steps,
+								  rtoffset);
 			}
 		}
 	}
diff --git a/src/test/regress/expected/partition_prune.out b/src/test/regress/expected/partition_prune.out
index 6e80947d874..1f31dd4cf24 100644
--- a/src/test/regress/expected/partition_prune.out
+++ b/src/test/regress/expected/partition_prune.out
@@ -1839,6 +1839,38 @@ explain (costs off) select * from rparted_by_int2 where a > 100000000000000;
 (2 rows)
 
 drop table lp, coll_pruning, rlp, mc3p, mc2p, boolpart, iboolpart, boolrangep, rp, coll_pruning_multi, like_op_noprune, lparted_by_int2, rparted_by_int2;
+-- check that AlternativeSubPlan within a pruning expression gets cleaned up
+create table asptab (id int primary key) partition by range (id);
+create table asptab0 partition of asptab for values from (0) to (1);
+create table asptab1 partition of asptab for values from (1) to (2);
+explain (costs off)
+select * from
+  (select exists (select 1 from int4_tbl tinner where f1 = touter.f1) as b
+   from int4_tbl touter) ss,
+  asptab
+where asptab.id > ss.b::int;
+                                        QUERY PLAN                                         
+-------------------------------------------------------------------------------------------
+ Nested Loop
+   ->  Seq Scan on int4_tbl touter
+   ->  Append
+         ->  Index Only Scan using asptab0_pkey on asptab0 asptab_1
+               Index Cond: (id > ((alternatives: SubPlan 3 or hashed SubPlan 4))::integer)
+               SubPlan 3
+                 ->  Seq Scan on int4_tbl tinner_2
+                       Filter: (f1 = touter.f1)
+               SubPlan 4
+                 ->  Seq Scan on int4_tbl tinner_3
+         ->  Index Only Scan using asptab1_pkey on asptab1 asptab_2
+               Index Cond: (id > ((alternatives: SubPlan 3 or hashed SubPlan 4))::integer)
+   SubPlan 1
+     ->  Seq Scan on int4_tbl tinner
+           Filter: (f1 = touter.f1)
+   SubPlan 2
+     ->  Seq Scan on int4_tbl tinner_1
+(17 rows)
+
+drop table asptab;
 --
 -- Test Partition pruning for HASH partitioning
 --
diff --git a/src/test/regress/sql/partition_prune.sql b/src/test/regress/sql/partition_prune.sql
index fec07a9a30b..d9e0fafbfb2 100644
--- a/src/test/regress/sql/partition_prune.sql
+++ b/src/test/regress/sql/partition_prune.sql
@@ -362,6 +362,21 @@ explain (costs off) select * from rparted_by_int2 where a > 100000000000000;
 
 drop table lp, coll_pruning, rlp, mc3p, mc2p, boolpart, iboolpart, boolrangep, rp, coll_pruning_multi, like_op_noprune, lparted_by_int2, rparted_by_int2;
 
+-- check that AlternativeSubPlan within a pruning expression gets cleaned up
+
+create table asptab (id int primary key) partition by range (id);
+create table asptab0 partition of asptab for values from (0) to (1);
+create table asptab1 partition of asptab for values from (1) to (2);
+
+explain (costs off)
+select * from
+  (select exists (select 1 from int4_tbl tinner where f1 = touter.f1) as b
+   from int4_tbl touter) ss,
+  asptab
+where asptab.id > ss.b::int;
+
+drop table asptab;
+
 --
 -- Test Partition pruning for HASH partitioning
 --