diff --git a/lisainstrument/dynamic_delay_dask.py b/lisainstrument/dynamic_delay_dask.py
index 144c25abd2c000741f97cf76271ac86f9705e9f0..5b8d6621e4bde74449e182c200ab362e12112ea4 100644
--- a/lisainstrument/dynamic_delay_dask.py
+++ b/lisainstrument/dynamic_delay_dask.py
@@ -5,7 +5,7 @@ Use make_dynamic_shift_lagrange_dask to create a Lagrange interpolator for dask
 
 from __future__ import annotations
 
-from typing import Any, Final
+from typing import Any, Callable, Final
 
 import dask
 import dask.array as da
@@ -14,7 +14,7 @@ from typing_extensions import assert_never
 
 from lisainstrument.dynamic_delay_numpy import DynShiftBC, DynShiftCfg
 from lisainstrument.fir_filters_dask import DaskArray1D, make_dask_array_1d
-from lisainstrument.fir_filters_numpy import NumpyArray1D, make_numpy_array_1d
+from lisainstrument.fir_filters_numpy import make_numpy_array_1d
 from lisainstrument.regular_interpolators import (
     RegularInterpolator,
     make_regular_interpolator_lagrange,
@@ -195,11 +195,9 @@ def make_dynamic_shift_lagrange_dask(
 
 
 def numpyfy_dask_multi(
-    # ~ dafunc: Callable[[*Any], DaskArray1D],
-    dafunc: Any,
+    dafunc: Callable,
     chunks: int,
-) -> Any:
-    # ~ ) -> Callable[[*Any], NumpyArray1D]:
+) -> Callable[[*Any], np.ndarray]:
     """Convert function operating on 1D dask arrays to work with 1D numpy arrays.
 
     Before calling the dask-based function, all arguments which are numpy
@@ -214,7 +212,7 @@ def numpyfy_dask_multi(
         function operating on numpy arrays
     """
 
-    def func(*args: Any) -> NumpyArray1D:
+    def func(*args: Any) -> np.ndarray:
         nargs = [
             (da.from_array(x, chunks=chunks) if isinstance(x, np.ndarray) else x)
             for x in args