diff --git a/backend/src/main/resources/db/migration/V39__modify_message_task_create_time.sql b/backend/src/main/resources/db/migration/V39__modify_message_task_create_time.sql
index 3235c4246d..74ecfc6196 100644
--- a/backend/src/main/resources/db/migration/V39__modify_message_task_create_time.sql
+++ b/backend/src/main/resources/db/migration/V39__modify_message_task_create_time.sql
@@ -1,2 +1,2 @@
-alter table message_task
-    add create_time bigint(13) null;
\ No newline at end of file
+ALTER TABLE message_task
+    ADD create_time bigint(13) DEFAULT 0;
\ No newline at end of file
diff --git a/backend/src/main/resources/db/migration/V41__modify_message_task_set.sql b/backend/src/main/resources/db/migration/V41__modify_message_task_set.sql
deleted file mode 100644
index 3e41e45e93..0000000000
--- a/backend/src/main/resources/db/migration/V41__modify_message_task_set.sql
+++ /dev/null
@@ -1,3 +0,0 @@
-alter table message_task
-    alter column create_time set default 0;
-