diff --git a/backend/packages/harness/deerflow/config/database_config.py b/backend/packages/harness/deerflow/config/database_config.py
index 37cfd579d..bcd869069 100644
--- a/backend/packages/harness/deerflow/config/database_config.py
+++ b/backend/packages/harness/deerflow/config/database_config.py
@@ -98,5 +98,8 @@ class DatabaseConfig(BaseModel):
             url = self.postgres_url
             if url.startswith("postgresql://"):
                 url = url.replace("postgresql://", "postgresql+asyncpg://", 1)
+            elif url.startswith("postgres://"):
+                # libpq's short alias: accepted by the psycopg checkpointer, but not a SQLAlchemy dialect.
+                url = url.replace("postgres://", "postgresql+asyncpg://", 1)
             return url
         raise ValueError(f"No SQLAlchemy URL for backend={self.backend!r}")
diff --git a/backend/tests/test_persistence_scaffold.py b/backend/tests/test_persistence_scaffold.py
index baba88c4b..ba460b9af 100644
--- a/backend/tests/test_persistence_scaffold.py
+++ b/backend/tests/test_persistence_scaffold.py
@@ -49,6 +49,15 @@ class TestDatabaseConfig:
         assert url.startswith("postgresql+asyncpg://")
         assert "u:p@h:5432/db" in url
 
+    def test_app_sqlalchemy_url_postgres_short_scheme(self):
+        c = DatabaseConfig(
+            backend="postgres",
+            postgres_url="postgres://u:p@h:5432/db",
+        )
+        url = c.app_sqlalchemy_url
+        assert url.startswith("postgresql+asyncpg://")
+        assert "u:p@h:5432/db" in url
+
     def test_app_sqlalchemy_url_postgres_already_asyncpg(self):
         c = DatabaseConfig(
             backend="postgres",