diff --git a/src/test/regress/expected/alter_table.out b/src/test/regress/expected/alter_table.out
index 41a7bcd6d0..b041247476 100644
--- a/src/test/regress/expected/alter_table.out
+++ b/src/test/regress/expected/alter_table.out
@@ -2437,51 +2437,96 @@ drop view at_view_2;
 drop view at_view_1;
 drop table at_base_table;
 -- check adding a column not iself requiring a rewrite, together with
--- a column requiring a default (bug #16038)
--- ensure that rewrites aren't silently optimized away, removing the
--- value of the test
-CREATE OR REPLACE FUNCTION evtrig_rewrite_log() RETURNS event_trigger
-LANGUAGE plpgsql AS $$
-BEGIN
-     RAISE WARNING 'rewriting table %',
-        pg_event_trigger_table_rewrite_oid()::regclass;
-END;
-$$;
-CREATE EVENT TRIGGER evtrig_rewrite_log ON table_rewrite
-    EXECUTE PROCEDURE evtrig_rewrite_log();
+-- a column requiring a default (bug #16038).  This checks
+-- pg_class.relfilenode before and after the rewrite for differences
+-- to see if a rewrite has been done or not.
 CREATE TABLE rewrite_test(col text);
 INSERT INTO rewrite_test VALUES ('something');
 INSERT INTO rewrite_test VALUES (NULL);
 -- empty[12] doesn't need rewrite, but notempty[12]_rewrite will force one
+SELECT relfilenode AS oldfilenode FROM pg_class
+    WHERE relname = 'rewrite_test'
+    \gset
 ALTER TABLE rewrite_test
     ADD COLUMN empty1 text,
     ADD COLUMN notempty1_rewrite serial;
-WARNING:  rewriting table rewrite_test
+SELECT relfilenode != :oldfilenode AS changed FROM pg_class
+    WHERE relname = 'rewrite_test';
+ changed 
+---------
+ t
+(1 row)
+
+SELECT relfilenode AS oldfilenode FROM pg_class
+    WHERE relname = 'rewrite_test'
+    \gset
 ALTER TABLE rewrite_test
     ADD COLUMN notempty2_rewrite serial,
     ADD COLUMN empty2 text;
-WARNING:  rewriting table rewrite_test
+SELECT relfilenode != :oldfilenode AS changed FROM pg_class
+    WHERE relname = 'rewrite_test';
+ changed 
+---------
+ t
+(1 row)
+
 -- also check that fast defaults cause no problem, first without rewrite
+SELECT relfilenode AS oldfilenode FROM pg_class
+    WHERE relname = 'rewrite_test'
+    \gset
 ALTER TABLE rewrite_test
     ADD COLUMN empty3 text,
     ADD COLUMN notempty3_norewrite int default 42;
+SELECT relfilenode != :oldfilenode AS changed FROM pg_class
+    WHERE relname = 'rewrite_test';
+ changed 
+---------
+ f
+(1 row)
+
+SELECT relfilenode AS oldfilenode FROM pg_class
+    WHERE relname = 'rewrite_test'
+    \gset
 ALTER TABLE rewrite_test
     ADD COLUMN notempty4_norewrite int default 42,
     ADD COLUMN empty4 text;
+SELECT relfilenode != :oldfilenode AS changed FROM pg_class
+    WHERE relname = 'rewrite_test';
+ changed 
+---------
+ f
+(1 row)
+
 -- then with rewrite
+SELECT relfilenode AS oldfilenode FROM pg_class
+    WHERE relname = 'rewrite_test'
+    \gset
 ALTER TABLE rewrite_test
     ADD COLUMN empty5 text,
     ADD COLUMN notempty5_norewrite int default 42,
     ADD COLUMN notempty5_rewrite serial;
-WARNING:  rewriting table rewrite_test
+SELECT relfilenode != :oldfilenode AS changed FROM pg_class
+    WHERE relname = 'rewrite_test';
+ changed 
+---------
+ t
+(1 row)
+
+SELECT relfilenode AS oldfilenode FROM pg_class
+    WHERE relname = 'rewrite_test'
+    \gset
 ALTER TABLE rewrite_test
     ADD COLUMN notempty6_rewrite serial,
     ADD COLUMN empty6 text,
     ADD COLUMN notempty6_norewrite int default 42;
-WARNING:  rewriting table rewrite_test
+SELECT relfilenode != :oldfilenode AS changed FROM pg_class
+    WHERE relname = 'rewrite_test';
+ changed 
+---------
+ t
+(1 row)
+
 -- cleanup
-drop event trigger evtrig_rewrite_log;
-drop function evtrig_rewrite_log();
 DROP TABLE rewrite_test;
 --
 -- lock levels
diff --git a/src/test/regress/sql/alter_table.sql b/src/test/regress/sql/alter_table.sql
index 3fde96b2b9..67672008ff 100644
--- a/src/test/regress/sql/alter_table.sql
+++ b/src/test/regress/sql/alter_table.sql
@@ -1551,51 +1551,71 @@ drop view at_view_1;
 drop table at_base_table;
 
 -- check adding a column not iself requiring a rewrite, together with
--- a column requiring a default (bug #16038)
-
--- ensure that rewrites aren't silently optimized away, removing the
--- value of the test
-CREATE OR REPLACE FUNCTION evtrig_rewrite_log() RETURNS event_trigger
-LANGUAGE plpgsql AS $$
-BEGIN
-     RAISE WARNING 'rewriting table %',
-        pg_event_trigger_table_rewrite_oid()::regclass;
-END;
-$$;
-CREATE EVENT TRIGGER evtrig_rewrite_log ON table_rewrite
-    EXECUTE PROCEDURE evtrig_rewrite_log();
-
+-- a column requiring a default (bug #16038).  This checks
+-- pg_class.relfilenode before and after the rewrite for differences
+-- to see if a rewrite has been done or not.
 CREATE TABLE rewrite_test(col text);
 INSERT INTO rewrite_test VALUES ('something');
 INSERT INTO rewrite_test VALUES (NULL);
 
 -- empty[12] doesn't need rewrite, but notempty[12]_rewrite will force one
+SELECT relfilenode AS oldfilenode FROM pg_class
+    WHERE relname = 'rewrite_test'
+    \gset
 ALTER TABLE rewrite_test
     ADD COLUMN empty1 text,
     ADD COLUMN notempty1_rewrite serial;
+SELECT relfilenode != :oldfilenode AS changed FROM pg_class
+    WHERE relname = 'rewrite_test';
+
+SELECT relfilenode AS oldfilenode FROM pg_class
+    WHERE relname = 'rewrite_test'
+    \gset
 ALTER TABLE rewrite_test
     ADD COLUMN notempty2_rewrite serial,
     ADD COLUMN empty2 text;
+SELECT relfilenode != :oldfilenode AS changed FROM pg_class
+    WHERE relname = 'rewrite_test';
+
 -- also check that fast defaults cause no problem, first without rewrite
+SELECT relfilenode AS oldfilenode FROM pg_class
+    WHERE relname = 'rewrite_test'
+    \gset
 ALTER TABLE rewrite_test
     ADD COLUMN empty3 text,
     ADD COLUMN notempty3_norewrite int default 42;
+SELECT relfilenode != :oldfilenode AS changed FROM pg_class
+    WHERE relname = 'rewrite_test';
+SELECT relfilenode AS oldfilenode FROM pg_class
+    WHERE relname = 'rewrite_test'
+    \gset
 ALTER TABLE rewrite_test
     ADD COLUMN notempty4_norewrite int default 42,
     ADD COLUMN empty4 text;
+SELECT relfilenode != :oldfilenode AS changed FROM pg_class
+    WHERE relname = 'rewrite_test';
+
 -- then with rewrite
+SELECT relfilenode AS oldfilenode FROM pg_class
+    WHERE relname = 'rewrite_test'
+    \gset
 ALTER TABLE rewrite_test
     ADD COLUMN empty5 text,
     ADD COLUMN notempty5_norewrite int default 42,
     ADD COLUMN notempty5_rewrite serial;
+SELECT relfilenode != :oldfilenode AS changed FROM pg_class
+    WHERE relname = 'rewrite_test';
+SELECT relfilenode AS oldfilenode FROM pg_class
+    WHERE relname = 'rewrite_test'
+    \gset
 ALTER TABLE rewrite_test
     ADD COLUMN notempty6_rewrite serial,
     ADD COLUMN empty6 text,
     ADD COLUMN notempty6_norewrite int default 42;
+SELECT relfilenode != :oldfilenode AS changed FROM pg_class
+    WHERE relname = 'rewrite_test';
 
 -- cleanup
-drop event trigger evtrig_rewrite_log;
-drop function evtrig_rewrite_log();
 DROP TABLE rewrite_test;
 
 --