diff --git a/brainpy/_src/math/op_register/base.py b/brainpy/_src/math/op_register/base.py
index 4dd176519..74fa1188c 100644
--- a/brainpy/_src/math/op_register/base.py
+++ b/brainpy/_src/math/op_register/base.py
@@ -227,3 +227,4 @@ def _transform_to_array(a):
 def _transform_to_shapedarray(a):
   return jax.core.ShapedArray(a.shape, a.dtype)
 
+