diff --git a/src/backend/partitioning/partprune.c b/src/backend/partitioning/partprune.c
index 752810d0e4..7fb53e6446 100644
--- a/src/backend/partitioning/partprune.c
+++ b/src/backend/partitioning/partprune.c
@@ -384,7 +384,7 @@ make_partitionedrel_pruneinfo(PlannerInfo *root, RelOptInfo *parentrel,
* because in later iterations of the loop for child partitions,
* we want to translate from parent to child variables.
*/
- if (parentrel != subpart)
+ if (!bms_equal(parentrel->relids, subpart->relids))
{
int nappinfos;
AppendRelInfo **appinfos = find_appinfos_by_relids(root,
diff --git a/src/test/regress/expected/partition_prune.out b/src/test/regress/expected/partition_prune.out
index 6428b3a516..1a784b2ced 100644
--- a/src/test/regress/expected/partition_prune.out
+++ b/src/test/regress/expected/partition_prune.out
@@ -2477,6 +2477,85 @@ deallocate ab_q2;
deallocate ab_q3;
deallocate ab_q4;
deallocate ab_q5;
+-- UPDATE on a partition subtree has been seen to have problems.
+insert into ab values (1,2);
+explain (analyze, costs off, summary off, timing off)
+update ab_a1 set b = 3 from ab where ab.a = 1 and ab.a = ab_a1.a;
+ QUERY PLAN
+-------------------------------------------------------------------------------------
+ Update on ab_a1 (actual rows=0 loops=1)
+ Update on ab_a1_b1
+ Update on ab_a1_b2
+ Update on ab_a1_b3
+ -> Nested Loop (actual rows=0 loops=1)
+ -> Append (actual rows=1 loops=1)
+ -> Bitmap Heap Scan on ab_a1_b1 ab_a1_b1_1 (actual rows=0 loops=1)
+ Recheck Cond: (a = 1)
+ -> Bitmap Index Scan on ab_a1_b1_a_idx (actual rows=0 loops=1)
+ Index Cond: (a = 1)
+ -> Bitmap Heap Scan on ab_a1_b2 ab_a1_b2_1 (actual rows=1 loops=1)
+ Recheck Cond: (a = 1)
+ Heap Blocks: exact=1
+ -> Bitmap Index Scan on ab_a1_b2_a_idx (actual rows=1 loops=1)
+ Index Cond: (a = 1)
+ -> Bitmap Heap Scan on ab_a1_b3 ab_a1_b3_1 (actual rows=0 loops=1)
+ Recheck Cond: (a = 1)
+ -> Bitmap Index Scan on ab_a1_b3_a_idx (actual rows=0 loops=1)
+ Index Cond: (a = 1)
+ -> Materialize (actual rows=0 loops=1)
+ -> Bitmap Heap Scan on ab_a1_b1 (actual rows=0 loops=1)
+ Recheck Cond: (a = 1)
+ -> Bitmap Index Scan on ab_a1_b1_a_idx (actual rows=0 loops=1)
+ Index Cond: (a = 1)
+ -> Nested Loop (actual rows=1 loops=1)
+ -> Append (actual rows=1 loops=1)
+ -> Bitmap Heap Scan on ab_a1_b1 ab_a1_b1_1 (actual rows=0 loops=1)
+ Recheck Cond: (a = 1)
+ -> Bitmap Index Scan on ab_a1_b1_a_idx (actual rows=0 loops=1)
+ Index Cond: (a = 1)
+ -> Bitmap Heap Scan on ab_a1_b2 ab_a1_b2_1 (actual rows=1 loops=1)
+ Recheck Cond: (a = 1)
+ Heap Blocks: exact=1
+ -> Bitmap Index Scan on ab_a1_b2_a_idx (actual rows=1 loops=1)
+ Index Cond: (a = 1)
+ -> Bitmap Heap Scan on ab_a1_b3 ab_a1_b3_1 (actual rows=0 loops=1)
+ Recheck Cond: (a = 1)
+ -> Bitmap Index Scan on ab_a1_b3_a_idx (actual rows=1 loops=1)
+ Index Cond: (a = 1)
+ -> Materialize (actual rows=1 loops=1)
+ -> Bitmap Heap Scan on ab_a1_b2 (actual rows=1 loops=1)
+ Recheck Cond: (a = 1)
+ Heap Blocks: exact=1
+ -> Bitmap Index Scan on ab_a1_b2_a_idx (actual rows=1 loops=1)
+ Index Cond: (a = 1)
+ -> Nested Loop (actual rows=0 loops=1)
+ -> Append (actual rows=1 loops=1)
+ -> Bitmap Heap Scan on ab_a1_b1 ab_a1_b1_1 (actual rows=0 loops=1)
+ Recheck Cond: (a = 1)
+ -> Bitmap Index Scan on ab_a1_b1_a_idx (actual rows=0 loops=1)
+ Index Cond: (a = 1)
+ -> Bitmap Heap Scan on ab_a1_b2 ab_a1_b2_1 (actual rows=1 loops=1)
+ Recheck Cond: (a = 1)
+ Heap Blocks: exact=1
+ -> Bitmap Index Scan on ab_a1_b2_a_idx (actual rows=1 loops=1)
+ Index Cond: (a = 1)
+ -> Bitmap Heap Scan on ab_a1_b3 ab_a1_b3_1 (actual rows=0 loops=1)
+ Recheck Cond: (a = 1)
+ -> Bitmap Index Scan on ab_a1_b3_a_idx (actual rows=1 loops=1)
+ Index Cond: (a = 1)
+ -> Materialize (actual rows=0 loops=1)
+ -> Bitmap Heap Scan on ab_a1_b3 (actual rows=0 loops=1)
+ Recheck Cond: (a = 1)
+ -> Bitmap Index Scan on ab_a1_b3_a_idx (actual rows=1 loops=1)
+ Index Cond: (a = 1)
+(65 rows)
+
+table ab;
+ a | b
+---+---
+ 1 | 3
+(1 row)
+
drop table ab, lprt_a;
-- Join
create table tbl1(col1 int);
diff --git a/src/test/regress/sql/partition_prune.sql b/src/test/regress/sql/partition_prune.sql
index fe19e8f65f..aea8871fd8 100644
--- a/src/test/regress/sql/partition_prune.sql
+++ b/src/test/regress/sql/partition_prune.sql
@@ -554,6 +554,12 @@ deallocate ab_q3;
deallocate ab_q4;
deallocate ab_q5;
+-- UPDATE on a partition subtree has been seen to have problems.
+insert into ab values (1,2);
+explain (analyze, costs off, summary off, timing off)
+update ab_a1 set b = 3 from ab where ab.a = 1 and ab.a = ab_a1.a;
+table ab;
+
drop table ab, lprt_a;
-- Join