diff --git a/src/test/regress/expected/multi_mx_hide_shard_names.out b/src/test/regress/expected/multi_mx_hide_shard_names.out
index a49629a27..1a885f120 100644
--- a/src/test/regress/expected/multi_mx_hide_shard_names.out
+++ b/src/test/regress/expected/multi_mx_hide_shard_names.out
@@ -109,6 +109,7 @@ EXPLAIN (COSTS OFF) INSERT INTO pg_class SELECT * FROM pg_class;
 
 -- Check that query that psql "\d test_table" does gets optimized to an index
 -- scan
+-- PG18+: the psql \d-style regex on pg_class can flip the plan to a Seq Scan
 EXPLAIN (COSTS OFF) SELECT c.oid,
   n.nspname,
   c.relname
diff --git a/src/test/regress/expected/multi_mx_hide_shard_names_0.out b/src/test/regress/expected/multi_mx_hide_shard_names_0.out
index bcc77db8f..21ae97d5a 100644
--- a/src/test/regress/expected/multi_mx_hide_shard_names_0.out
+++ b/src/test/regress/expected/multi_mx_hide_shard_names_0.out
@@ -109,6 +109,7 @@ EXPLAIN (COSTS OFF) INSERT INTO pg_class SELECT * FROM pg_class;
 
 -- Check that query that psql "\d test_table" does gets optimized to an index
 -- scan
+-- PG18+: the psql \d-style regex on pg_class can flip the plan to a Seq Scan
 EXPLAIN (COSTS OFF) SELECT c.oid,
   n.nspname,
   c.relname
diff --git a/src/test/regress/sql/multi_mx_hide_shard_names.sql b/src/test/regress/sql/multi_mx_hide_shard_names.sql
index c275f3b0b..20068e0bb 100644
--- a/src/test/regress/sql/multi_mx_hide_shard_names.sql
+++ b/src/test/regress/sql/multi_mx_hide_shard_names.sql
@@ -60,6 +60,7 @@ EXPLAIN (COSTS OFF) INSERT INTO pg_class SELECT * FROM pg_class;
 
 -- Check that query that psql "\d test_table" does gets optimized to an index
 -- scan
+-- PG18+: the psql \d-style regex on pg_class can flip the plan to a Seq Scan
 EXPLAIN (COSTS OFF) SELECT c.oid,
   n.nspname,
   c.relname