diff --git a/api/db/db_models.py b/api/db/db_models.py
index bb58f181f1..da0f741e78 100644
--- a/api/db/db_models.py
+++ b/api/db/db_models.py
@@ -1741,9 +1741,9 @@ def migrate_db():
     alter_db_add_column(migrator, "knowledgebase", "graphrag_task_id", CharField(max_length=32, null=True, help_text="Gragh RAG task ID", index=True))
     alter_db_add_column(migrator, "knowledgebase", "raptor_task_id", CharField(max_length=32, null=True, help_text="RAPTOR task ID", index=True))
     alter_db_add_column(migrator, "knowledgebase", "graphrag_task_finish_at", DateTimeField(null=True))
-    alter_db_add_column(migrator, "knowledgebase", "raptor_task_finish_at", CharField(null=True))
+    alter_db_add_column(migrator, "knowledgebase", "raptor_task_finish_at", DateTimeField(null=True))
     alter_db_add_column(migrator, "knowledgebase", "mindmap_task_id", CharField(max_length=32, null=True, help_text="Mindmap task ID", index=True))
-    alter_db_add_column(migrator, "knowledgebase", "mindmap_task_finish_at", CharField(null=True))
+    alter_db_add_column(migrator, "knowledgebase", "mindmap_task_finish_at", DateTimeField(null=True))
     alter_db_add_column(migrator, "knowledgebase", "artifact_task_id", CharField(max_length=32, null=True, help_text="Artifact compilation task ID", index=True))
     alter_db_add_column(migrator, "knowledgebase", "artifact_task_finish_at", DateTimeField(null=True))
     alter_db_add_column(migrator, "knowledgebase", "skill_task_id", CharField(max_length=32, null=True, help_text="Skill generation task ID", index=True))