diff --git a/src/backend/optimizer/plan/initsplan.c b/src/backend/optimizer/plan/initsplan.c
index e5b3cb5fcc3..a80d4e1681e 100644
--- a/src/backend/optimizer/plan/initsplan.c
+++ b/src/backend/optimizer/plan/initsplan.c
@@ -1432,6 +1432,13 @@ make_outerjoininfo(PlannerInfo *root,
 	 */
 	strict_relids = find_nonnullable_rels((Node *) clause);
 
+	/*
+	 * find_nonnullable_rels looks inside PlaceHolderVars, so it can report
+	 * rels that the clause references only laterally.  Ignore those, since
+	 * like clause_relids we treat a PHV as computed at its ph_eval_at.
+	 */
+	strict_relids = bms_int_members(strict_relids, clause_relids);
+
 	/* Remember whether the clause is strict for any LHS relations */
 	sjinfo->lhs_strict = bms_overlap(strict_relids, left_rels);
 
diff --git a/src/test/regress/expected/join.out b/src/test/regress/expected/join.out
index b8829c97616..19d92a82607 100644
--- a/src/test/regress/expected/join.out
+++ b/src/test/regress/expected/join.out
@@ -5797,6 +5797,36 @@ where s2.q2 > t1.f1;
 (1 row)
 
 reset from_collapse_limit;
+--
+-- check that an outer join is not taken to commute with a lower outer join
+-- when its clause references the lower join's RHS only laterally within a
+-- PlaceHolderVar
+--
+explain (costs off)
+select 1 from int4_tbl t1
+  left join int4_tbl t2 on true
+  left join lateral (select t2.f1, 1 from int4_tbl t3) s(x, y) on true
+  left join int4_tbl t4 on t4.f1 = s.x
+  join int4_tbl t5 on true
+where s.y is not null;
+                      QUERY PLAN                       
+-------------------------------------------------------
+ Nested Loop
+   ->  Hash Left Join
+         Hash Cond: ((t2.f1) = t4.f1)
+         ->  Nested Loop
+               ->  Nested Loop Left Join
+                     ->  Seq Scan on int4_tbl t1
+                     ->  Materialize
+                           ->  Seq Scan on int4_tbl t2
+               ->  Seq Scan on int4_tbl t3
+                     Filter: (1 IS NOT NULL)
+         ->  Hash
+               ->  Seq Scan on int4_tbl t4
+   ->  Materialize
+         ->  Seq Scan on int4_tbl t5
+(14 rows)
+
 --
 -- test successful handling of full join underneath left join (bug #14105)
 --
diff --git a/src/test/regress/sql/join.sql b/src/test/regress/sql/join.sql
index f8fc1ddd742..d536f17d897 100644
--- a/src/test/regress/sql/join.sql
+++ b/src/test/regress/sql/join.sql
@@ -2044,6 +2044,20 @@ where s2.q2 > t1.f1;
 
 reset from_collapse_limit;
 
+--
+-- check that an outer join is not taken to commute with a lower outer join
+-- when its clause references the lower join's RHS only laterally within a
+-- PlaceHolderVar
+--
+
+explain (costs off)
+select 1 from int4_tbl t1
+  left join int4_tbl t2 on true
+  left join lateral (select t2.f1, 1 from int4_tbl t3) s(x, y) on true
+  left join int4_tbl t4 on t4.f1 = s.x
+  join int4_tbl t5 on true
+where s.y is not null;
+
 --
 -- test successful handling of full join underneath left join (bug #14105)
 --