diff --git a/tests/test_shift_inversion_dask.py b/tests/test_shift_inversion_dask.py
index 0f9a423cd275908120962f6ebe07519eccca5658..903acf16b084781c062f5370f5571e06b6f19a06 100644
--- a/tests/test_shift_inversion_dask.py
+++ b/tests/test_shift_inversion_dask.py
@@ -25,8 +25,8 @@ def test_shift_inversion_numpy():
     fsample = 1 / dt
     dxi = dx_from_x(xi)
 
-    op_np = make_shift_inverse_lagrange_numpy(order, a_mod * 1.01, max_it, tol)
-    op_da = make_shift_inverse_lagrange_dask(order, a_mod * 1.01, max_it, tol)
+    op_np = make_shift_inverse_lagrange_numpy(order, a_mod * 1.01 / dt, max_it, tol)
+    op_da = make_shift_inverse_lagrange_dask(order, a_mod * 1.01 / dt, max_it, tol)
     op_na = numpyfy_dask_multi(op_da, chunks)
 
     ai_np = op_np(dxi, fsample)
diff --git a/tests/test_shift_inversion_numpy.py b/tests/test_shift_inversion_numpy.py
index 0259c5c915e873febd061e1b7173a9e05df306d7..d91baac557d6b61ccfbe5ad0c12a23360e4fc325 100644
--- a/tests/test_shift_inversion_numpy.py
+++ b/tests/test_shift_inversion_numpy.py
@@ -22,7 +22,7 @@ def test_shift_inversion_numpy():
     fsample = 1 / dt
     dxi = dx_from_x(xi)
 
-    op_np = make_shift_inverse_lagrange_numpy(order, a_mod * 1.01, max_it, tol)
+    op_np = make_shift_inverse_lagrange_numpy(order, a_mod * 1.01 / dt, max_it, tol)
 
     ai_np = op_np(dxi, fsample)