diff --git a/brainpy/_src/dependency_check.py b/brainpy/_src/dependency_check.py
index 183e99d9..2babb502 100644
--- a/brainpy/_src/dependency_check.py
+++ b/brainpy/_src/dependency_check.py
@@ -17,7 +17,7 @@
   'import_brainpylib_gpu_ops',
 ]
 
-_minimal_brainpylib_version = '0.1.10'
+_minimal_brainpylib_version = '0.2.6'
 _minimal_taichi_version = (1, 7, 0)
 
 taichi = None
diff --git a/brainpy/_src/dnn/tests/test_linear.py b/brainpy/_src/dnn/tests/test_linear.py
index 41844cc8..422f161f 100644
--- a/brainpy/_src/dnn/tests/test_linear.py
+++ b/brainpy/_src/dnn/tests/test_linear.py
@@ -1,7 +1,8 @@
 import pytest
-import brainpy as bp
-from absl.testing import parameterized
 from absl.testing import absltest
+from absl.testing import parameterized
+
+import brainpy as bp
 import brainpy.math as bm
 
 from brainpy._src.dependency_check import import_taichi
diff --git a/brainpy/_src/dnn/tests/test_mode.py b/brainpy/_src/dnn/tests/test_mode.py
index 0c010757..f0c67da1 100644
--- a/brainpy/_src/dnn/tests/test_mode.py
+++ b/brainpy/_src/dnn/tests/test_mode.py
@@ -1,10 +1,12 @@
 import pytest
-import brainpy.math as bm
-from absl.testing import parameterized
 from absl.testing import absltest
+from absl.testing import parameterized
+
 import brainpy as bp
+import brainpy.math as bm
 
 from brainpy._src.dependency_check import import_taichi
+
 if import_taichi(error_if_not_found=False) is None:
   pytest.skip('no taichi', allow_module_level=True)