diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 7b2dc4358d..9287670948 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -20,8 +20,8 @@ repos:
     hooks:
       - id: pyupgrade
         args: [--py37-plus]
-  - repo: https://github.com/psf/black
-    rev: 25.1.0
+  - repo: https://github.com/psf/black-pre-commit-mirror
+    rev: 26.5.1
     hooks:
       - id: black
   - repo: https://github.com/PyCQA/flake8
diff --git a/finrl/meta/env_stock_trading/env_nas100_wrds.py b/finrl/meta/env_stock_trading/env_nas100_wrds.py
index 47a8b2b81f..69c7719ca2 100644
--- a/finrl/meta/env_stock_trading/env_nas100_wrds.py
+++ b/finrl/meta/env_stock_trading/env_nas100_wrds.py
@@ -36,7 +36,7 @@ def __init__(
         self.min_stock_rate = min_stock_rate
         beg_i, mid_i, end_i = 0, int(211210), int(422420)
 
-        (i0, i1) = (beg_i, mid_i) if if_eval else (mid_i, end_i)
+        i0, i1 = (beg_i, mid_i) if if_eval else (mid_i, end_i)
         data_arrays = (
             self.load_data(cwd) if cwd is not None else price_ary,
             tech_ary,
diff --git a/finrl/meta/paper_trading/common.py b/finrl/meta/paper_trading/common.py
index aae4c52220..469181e845 100644
--- a/finrl/meta/paper_trading/common.py
+++ b/finrl/meta/paper_trading/common.py
@@ -11,7 +11,6 @@
 from torch import Tensor
 from torch.distributions.normal import Normal
 
-
 # -----------------------------------------------------------------------------------------------------------------------------------------
 # PPO
 
diff --git a/finrl/meta/preprocessor/example_of_shioaji_api.py b/finrl/meta/preprocessor/example_of_shioaji_api.py
index a5b51888e3..010ec56537 100644
--- a/finrl/meta/preprocessor/example_of_shioaji_api.py
+++ b/finrl/meta/preprocessor/example_of_shioaji_api.py
@@ -9,7 +9,6 @@
 from finrl.meta.preprocessor.preprocessors import data_split
 from finrl.meta.preprocessor.shioajidownloader import SinopacDownloader
 
-
 TRAIN_START_DATE = "2023-04-13"
 TRAIN_END_DATE = "2024-04-13"
 TRADE_START_DATE = "2024-04-13"
diff --git a/unit_tests/downloaders/test_alpaca_downloader.py b/unit_tests/downloaders/test_alpaca_downloader.py
index e82c37e61e..69df8d24fc 100644
--- a/unit_tests/downloaders/test_alpaca_downloader.py
+++ b/unit_tests/downloaders/test_alpaca_downloader.py
@@ -5,7 +5,6 @@
 
 from finrl.meta.data_processors.processor_alpaca import AlpacaProcessor
 
-
 API_KEY = "???"
 API_SECRET = "???"
 API_BASE_URL = "https://paper-api.alpaca.markets"