diff --git a/tests/pytest/dbmgmt/nanoSecondCheck.py b/tests/pytest/dbmgmt/nanoSecondCheck.py
index 27050a2213f7e6bddeb5cc6135c7fe4760018f61..a5e9adacee53a9172a2d8990ccc4d83feb983bdd 100644
--- a/tests/pytest/dbmgmt/nanoSecondCheck.py
+++ b/tests/pytest/dbmgmt/nanoSecondCheck.py
@@ -99,6 +99,15 @@ class TDTestCase:
         tdSql.query('select avg(speed) from tb interval(100000000b)')
         tdSql.checkRows(4)
 
+        tdSql.error('select avg(speed) from tb interval(1b);')
+        tdSql.error('select avg(speed) from tb interval(999b);')
+
+        tdSql.query('select avg(speed) from tb interval(1000b);')
+        tdSql.checkRows(5)
+
+        tdSql.query('select avg(speed) from tb interval(1u);')
+        tdSql.checkRows(5)
+
         tdSql.query('select avg(speed) from tb interval(100000000b) sliding (100000000b);')
         tdSql.checkRows(4)