diff --git a/src/test/regress/expected/transactions.out b/src/test/regress/expected/transactions.out
index 75dc6558d82..61862d595d1 100644
--- a/src/test/regress/expected/transactions.out
+++ b/src/test/regress/expected/transactions.out
@@ -1026,6 +1026,7 @@ SHOW transaction_isolation;  -- transaction is active at this point
 (1 row)
 
 ROLLBACK;
+SET default_transaction_isolation = 'read committed';
 -- START TRANSACTION + COMMIT/ROLLBACK + COMMIT/ROLLBACK AND CHAIN
 START TRANSACTION ISOLATION LEVEL REPEATABLE READ\; INSERT INTO abc VALUES (17)\; COMMIT\; INSERT INTO abc VALUES (18)\; COMMIT AND CHAIN;  -- 17 commit, 18 error
 ERROR:  COMMIT AND CHAIN can only be used in transaction blocks
@@ -1043,6 +1044,7 @@ SHOW transaction_isolation;  -- out of transaction block
  read committed
 (1 row)
 
+RESET default_transaction_isolation;
 SELECT * FROM abc ORDER BY 1;
  a  
 ----
diff --git a/src/test/regress/sql/transactions.sql b/src/test/regress/sql/transactions.sql
index d1b6ed0280d..8886280c0a6 100644
--- a/src/test/regress/sql/transactions.sql
+++ b/src/test/regress/sql/transactions.sql
@@ -578,6 +578,8 @@ START TRANSACTION ISOLATION LEVEL REPEATABLE READ\; INSERT INTO abc VALUES (16)\
 SHOW transaction_isolation;  -- transaction is active at this point
 ROLLBACK;
 
+SET default_transaction_isolation = 'read committed';
+
 -- START TRANSACTION + COMMIT/ROLLBACK + COMMIT/ROLLBACK AND CHAIN
 START TRANSACTION ISOLATION LEVEL REPEATABLE READ\; INSERT INTO abc VALUES (17)\; COMMIT\; INSERT INTO abc VALUES (18)\; COMMIT AND CHAIN;  -- 17 commit, 18 error
 SHOW transaction_isolation;  -- out of transaction block
@@ -585,6 +587,8 @@ SHOW transaction_isolation;  -- out of transaction block
 START TRANSACTION ISOLATION LEVEL REPEATABLE READ\; INSERT INTO abc VALUES (19)\; ROLLBACK\; INSERT INTO abc VALUES (20)\; ROLLBACK AND CHAIN;  -- 19 rollback, 20 error
 SHOW transaction_isolation;  -- out of transaction block
 
+RESET default_transaction_isolation;
+
 SELECT * FROM abc ORDER BY 1;
 
 DROP TABLE abc;