diff --git a/src/test/regress/expected/merge.out b/src/test/regress/expected/merge.out
index 9cb1d870..4441e399 100644
--- a/src/test/regress/expected/merge.out
+++ b/src/test/regress/expected/merge.out
@@ -1609,6 +1609,31 @@ LATERAL (SELECT r_action, r_tid, r_balance FROM merge_into_sq_target(sid, balanc
  INSERT   |     4 |       110
 (3 rows)
 
+ROLLBACK;
+-- Test that old/new column IS NULL is constant-folded
+-- for NOT NULL columns in MERGE RETURNING
+BEGIN;
+MERGE INTO sq_target t
+USING sq_source s ON tid = sid
+WHEN MATCHED AND tid >= 2 THEN
+    UPDATE SET balance = t.balance + delta
+WHEN NOT MATCHED THEN
+    INSERT (balance, tid) VALUES (balance + delta, sid)
+WHEN MATCHED AND tid < 2 THEN
+    DELETE
+RETURNING merge_action(),
+    old.tid IS NULL AS old_tid_is_null,
+    new.tid IS NULL AS new_tid_is_null,
+    old IS NULL AS old_row_is_null,
+    new IS NULL AS new_row_is_null;
+ merge_action | old_tid_is_null | new_tid_is_null | old_row_is_null | new_row_is_null 
+--------------+-----------------+-----------------+-----------------+-----------------
+ DELETE       | f               | t               | f               | t
+ UPDATE       | f               | f               | f               | f
+ INSERT       | t               | f               | t               | f
+(3 rows)
+
 ROLLBACK;
 -- EXPLAIN
 CREATE TABLE ex_mtarget (a int, b int)
diff --git a/src/test/regress/sql/merge.sql b/src/test/regress/sql/merge.sql
index 2660b19f..6789fcd5 100644
--- a/src/test/regress/sql/merge.sql
+++ b/src/test/regress/sql/merge.sql
@@ -1060,6 +1060,25 @@ FROM (VALUES (1, 0, 0), (3, 0, 20), (4, 100, 10)) AS v(sid, balance, delta),
 LATERAL (SELECT r_action, r_tid, r_balance FROM merge_into_sq_target(sid, balance, delta)) m;
 ROLLBACK;
 
+-- Test that old/new column IS NULL is constant-folded
+-- for NOT NULL columns in MERGE RETURNING
+BEGIN;
+MERGE INTO sq_target t
+USING sq_source s ON tid = sid
+WHEN MATCHED AND tid >= 2 THEN
+    UPDATE SET balance = t.balance + delta
+WHEN NOT MATCHED THEN
+    INSERT (balance, tid) VALUES (balance + delta, sid)
+WHEN MATCHED AND tid < 2 THEN
+    DELETE
+RETURNING merge_action(),
+    old.tid IS NULL AS old_tid_is_null,
+    new.tid IS NULL AS new_tid_is_null,
+    old IS NULL AS old_row_is_null,
+    new IS NULL AS new_row_is_null;
+ROLLBACK;
+
 -- EXPLAIN
 CREATE TABLE ex_mtarget (a int, b int)
   WITH (autovacuum_enabled=off);