diff --git a/src/test/regress/expected/alter_table.out b/src/test/regress/expected/alter_table.out
index 268720168e..065ac77730 100644
--- a/src/test/regress/expected/alter_table.out
+++ b/src/test/regress/expected/alter_table.out
@@ -243,7 +243,7 @@ ALTER INDEX alter_idx_rename_test_parted RENAME TO alter_idx_rename_test_parted_
 SELECT relation::regclass, mode FROM pg_locks
 WHERE pid = pg_backend_pid() AND locktype = 'relation'
   AND relation::regclass::text LIKE 'alter\_idx%'
-ORDER BY relation::regclass::text;
+ORDER BY relation::regclass::text COLLATE "C";
             relation            |        mode         
 --------------------------------+---------------------
  alter_idx_rename_test_2        | AccessExclusiveLock
@@ -257,7 +257,7 @@ ALTER INDEX alter_idx_rename_test_parted_idx RENAME TO alter_idx_rename_test_par
 SELECT relation::regclass, mode FROM pg_locks
 WHERE pid = pg_backend_pid() AND locktype = 'relation'
   AND relation::regclass::text LIKE 'alter\_idx%'
-ORDER BY relation::regclass::text;
+ORDER BY relation::regclass::text COLLATE "C";
               relation              |           mode           
 ------------------------------------+--------------------------
  alter_idx_rename_test_idx_2        | ShareUpdateExclusiveLock
@@ -271,7 +271,7 @@ ALTER TABLE alter_idx_rename_test_parted_idx_2 RENAME TO alter_idx_rename_test_p
 SELECT relation::regclass, mode FROM pg_locks
 WHERE pid = pg_backend_pid() AND locktype = 'relation'
   AND relation::regclass::text LIKE 'alter\_idx%'
-ORDER BY relation::regclass::text;
+ORDER BY relation::regclass::text COLLATE "C";
               relation              |        mode         
 ------------------------------------+---------------------
  alter_idx_rename_test_idx_3        | AccessExclusiveLock
diff --git a/src/test/regress/sql/alter_table.sql b/src/test/regress/sql/alter_table.sql
index 45cb960db0..fa8308a1e1 100644
--- a/src/test/regress/sql/alter_table.sql
+++ b/src/test/regress/sql/alter_table.sql
@@ -238,7 +238,7 @@ ALTER INDEX alter_idx_rename_test_parted RENAME TO alter_idx_rename_test_parted_
 SELECT relation::regclass, mode FROM pg_locks
 WHERE pid = pg_backend_pid() AND locktype = 'relation'
   AND relation::regclass::text LIKE 'alter\_idx%'
-ORDER BY relation::regclass::text;
+ORDER BY relation::regclass::text COLLATE "C";
 COMMIT;
 BEGIN;
 ALTER INDEX alter_idx_rename_test_idx RENAME TO alter_idx_rename_test_idx_2;
@@ -246,7 +246,7 @@ ALTER INDEX alter_idx_rename_test_parted_idx RENAME TO alter_idx_rename_test_par
 SELECT relation::regclass, mode FROM pg_locks
 WHERE pid = pg_backend_pid() AND locktype = 'relation'
   AND relation::regclass::text LIKE 'alter\_idx%'
-ORDER BY relation::regclass::text;
+ORDER BY relation::regclass::text COLLATE "C";
 COMMIT;
 BEGIN;
 ALTER TABLE alter_idx_rename_test_idx_2 RENAME TO alter_idx_rename_test_idx_3;
@@ -254,7 +254,7 @@ ALTER TABLE alter_idx_rename_test_parted_idx_2 RENAME TO alter_idx_rename_test_p
 SELECT relation::regclass, mode FROM pg_locks
 WHERE pid = pg_backend_pid() AND locktype = 'relation'
   AND relation::regclass::text LIKE 'alter\_idx%'
-ORDER BY relation::regclass::text;
+ORDER BY relation::regclass::text COLLATE "C";
 COMMIT;
 DROP TABLE alter_idx_rename_test_2;