diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index 15120b8758..fd712e92fe 100644
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -1578,3 +1578,4 @@ SELECT '' AS to_timestamp_8, to_timestamp('2000January09Sunday', 'YYYYFMMonthDDF
                 | Sun Jan 09 00:00:00 2000 PST
 (1 row)
 
+SET DateStyle TO DEFAULT;
diff --git a/src/test/regress/sql/timestamp.sql b/src/test/regress/sql/timestamp.sql
index ae97dfd320..97b01f9f55 100644
--- a/src/test/regress/sql/timestamp.sql
+++ b/src/test/regress/sql/timestamp.sql
@@ -222,3 +222,5 @@ SELECT '' AS to_timestamp_6, to_timestamp('15 "text bettween quote marks" 98 54
 SELECT '' AS to_timestamp_7, to_timestamp('05121445482000', 'MMDDHHMISSYYYY');    
 
 SELECT '' AS to_timestamp_8, to_timestamp('2000January09Sunday', 'YYYYFMMonthDDFMDay');
+
+SET DateStyle TO DEFAULT;