diff --git a/tests/test_dynamic_delay_dask.py b/tests/test_dynamic_delay_dask.py
index f21a36d030a71387eb0db61539c7c5cc39fa2299..7f3b12f749f33a9c25e33addc5c938364e11ea08 100644
--- a/tests/test_dynamic_delay_dask.py
+++ b/tests/test_dynamic_delay_dask.py
@@ -4,16 +4,16 @@ import pytest
 from lisainstrument.dynamic_delay_dask import (
     make_dynamic_shift_lagrange_dask,
     make_dynamic_shift_linear_dask,
-    numpyfy_dask_bivariate,
+    numpyfy_dask_multi,
 )
 from lisainstrument.dynamic_delay_numpy import (
     DynShiftBC,
     make_dynamic_shift_lagrange_numpy,
-    make_lagrange_polynomials,
 )
+from lisainstrument.regular_interpolators import make_lagrange_polynomials
 
 
-def test_dynamic_shift_linear_dask():
+def test_dynamic_shift_linear_dask() -> None:
     t, dt = np.linspace(-5.345, 10.345, 103, retstep=True)
 
     def g(x):
@@ -28,7 +28,7 @@ def test_dynamic_shift_linear_dask():
     op_da = make_dynamic_shift_linear_dask(
         d.min(), d.max(), DynShiftBC.FLAT, DynShiftBC.EXCEPTION
     )
-    op_np = numpyfy_dask_bivariate(op_da, chunks=19)
+    op_np = numpyfy_dask_multi(op_da, chunks=19)
 
     s_da = op_np(y, d)
     s_ex = g(np.maximum(t[0], t - d * dt))
@@ -36,28 +36,32 @@ def test_dynamic_shift_linear_dask():
     assert s_ex == pytest.approx(s_da, abs=1e-15, rel=1e-14)
 
 
-def test_dynamic_shift_lagrange_dask():
+def test_dynamic_shift_lagrange_dask() -> None:
     order = 5
     length = order + 1
 
     t, dt = np.linspace(-5.345, 10.345, 1003, retstep=True)
 
     def g(x):
-        n = x / 10.0
-        return 4.32546 + 3.34324 * x + 4.342 * x**2 + 0.46 * x**3 + 1.43598 * x**4 + 3.3456 * x**5
+        return (
+            4.32546
+            + 3.34324 * x
+            + 4.342 * x**2
+            + 0.46 * x**3
+            + 1.43598 * x**4
+            + 3.3456 * x**5
+        )
 
     y = g(t)
 
     d = (0.93456456 + 0.0235345 * np.cos(4.3354 * t)) / dt
 
-    # ~ print(y[0], t[0], d[0])
-
     op_da = make_dynamic_shift_lagrange_dask(
         length, d.min(), d.max(), DynShiftBC.FLAT, DynShiftBC.EXCEPTION
     )
-    op_na = numpyfy_dask_bivariate(op_da, chunks=19)
+    op_na = numpyfy_dask_multi(op_da, chunks=19)
 
-    s_da = op_na(y, d)
+    s_da: np.ndarray = op_na(y, d)
     s_ex = g(np.maximum(t[0], t - d * dt))
 
     assert s_ex[op_da.margin_left :] == pytest.approx(
@@ -73,6 +77,7 @@ def test_dynamic_shift_lagrange_dask():
     assert np.all(s_np == s_da)
 
 
+
 def test_lagrange_polynomials():
     length = 11
     d = -(length // 2)