diff --git a/tests/system-test/1-insert/alter_database.py b/tests/system-test/1-insert/alter_database.py
index 12b886170711e74c40c5085f7d99a813051af45d..1fca294a47475e7353688bf36a916e2af92d5adb 100644
--- a/tests/system-test/1-insert/alter_database.py
+++ b/tests/system-test/1-insert/alter_database.py
@@ -18,7 +18,7 @@ class TDTestCase:
         tdSql.init(conn.cursor(), logSql)
         self.buffer_boundary = [3, 4097, 8193, 12289, 16384]
         self.buffer_error = [self.buffer_boundary[0] -
-                             1, self.buffer_boundary[-1]+1, 12289, 256]
+                             1, self.buffer_boundary[-1]+1, 256]
         # pages_boundary >= 64
         self.pages_boundary = [64, 128, 512]
         self.pages_error = [self.pages_boundary[0]-1]