diff --git a/sqladmin/models.py b/sqladmin/models.py
index 016a6613..f0e9fe33 100644
--- a/sqladmin/models.py
+++ b/sqladmin/models.py
@@ -1183,15 +1183,15 @@ async def generate(writer: Writer) -> AsyncGenerator[Any, None]:
         )
 
     async def _export_json(
-            self,
-            data: List[Any],
+        self,
+        data: List[Any],
     ) -> StreamingResponse:
         async def generate() -> AsyncGenerator[str, None]:
-            yield '['
+            yield "["
             first_row = True
             for row in data:
                 if not first_row:
-                    yield ','
+                    yield ","
                 else:
                     first_row = False
                 row_dict = {
@@ -1199,7 +1199,8 @@ async def generate() -> AsyncGenerator[str, None]:
                     for name in self._export_prop_names
                 }
                 yield json.dumps(row_dict)
-            yield ']'
+            yield "]"
+
         filename = secure_filename(self.get_export_name(export_type="json"))
         return StreamingResponse(
             content=generate(),
diff --git a/tests/test_views/test_view_sync.py b/tests/test_views/test_view_sync.py
index 6ddc6099..a9904ab0 100644
--- a/tests/test_views/test_view_sync.py
+++ b/tests/test_views/test_view_sync.py
@@ -740,6 +740,7 @@ def test_export_json(client: TestClient) -> None:
     response = client.get("/admin/user/export/json")
     assert response.text == '[{"name": "Daniel", "status": "ACTIVE"}]'
 
+
 def test_export_csv_row_count(client: TestClient) -> None:
     def row_count(resp) -> int:
         return resp.text.count("\r\n") - 1