diff --git a/.gitignore b/.gitignore
index 7088d3650..65136a406 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,7 +4,6 @@ _version.py
 .DS_Store
 .envrc
 .hypothesis
-.mypy_cache
 .pytest_cache
 .vscode
 *.aux
diff --git a/pyproject.toml b/pyproject.toml
index ab787d24c..e6aae2e30 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -96,23 +96,6 @@ run = {branch = true, parallel = true, source = [
     "sleplet",
 ]}
 
-[tool.mypy]
-disallow_subclassing_any = false
-disallow_untyped_decorators = false
-enable_error_code = [
-    "ignore-without-code",
-    "redundant-expr",
-    "truthy-bool",
-]
-explicit_package_bases = true
-ignore_missing_imports = true
-plugins = [
-    "pydantic.mypy",
-]
-strict = true
-warn_return_any = false
-warn_unreachable = true
-
 [tool.pytest.ini_options]
 addopts = [
     "--color=yes",
@@ -191,3 +174,11 @@ write_to = "src/sleplet/_version.py"
 [tool.tomlsort]
 overrides."project.classifiers".inline_arrays = false
 overrides."tool.ruff.lint.isort.section-order".inline_arrays = false
+
+[tool.ty]
+rules.invalid-argument-type = "ignore"
+rules.unresolved-attribute = "ignore"
+src.include = [
+    "src",
+    "tests",
+]
diff --git a/src/sleplet/_convolution_methods.py b/src/sleplet/_convolution_methods.py
index ade3c1645..f49c33e69 100644
--- a/src/sleplet/_convolution_methods.py
+++ b/src/sleplet/_convolution_methods.py
@@ -16,4 +16,4 @@ def sifting_convolution(
         if len(g_coefficient.shape) < len(f_coefficient.shape)
         else g_coefficient
     )
-    return (f_coefficient.T[:n] * g_reshape.conj().T[:n]).T  # type: ignore[return-value]
+    return (f_coefficient.T[:n] * g_reshape.conj().T[:n]).T  # ty: ignore[invalid-return-type]
diff --git a/src/sleplet/_data/setup_pooch.py b/src/sleplet/_data/setup_pooch.py
index 4b2bd7c2d..8aa9df68e 100644
--- a/src/sleplet/_data/setup_pooch.py
+++ b/src/sleplet/_data/setup_pooch.py
@@ -65,10 +65,10 @@ def find_on_pooch_then_local(filename: str) -> os.PathLike[str] | None:
     Returns:
         The sought after file or nothing if not found
     """
-    if filename in _POOCH.registry:  # type: ignore[union-attr]
+    if filename in _POOCH.registry:
         msg = f"Found {filename} at https://doi.org/{_ZENODO_DATA_DOI}"
         _logger.info(msg)
-        return _POOCH.fetch(filename, progressbar=True)  # type: ignore[union-attr]
+        return _POOCH.fetch(filename, progressbar=True)
 
     if (platformdirs.user_data_path() / filename).exists():
         msg = f"Found {filename} at {platformdirs.user_data_path() / filename}"
diff --git a/src/sleplet/_mesh_methods.py b/src/sleplet/_mesh_methods.py
index d461d3f72..acee7fca1 100644
--- a/src/sleplet/_mesh_methods.py
+++ b/src/sleplet/_mesh_methods.py
@@ -113,12 +113,12 @@ def mesh_eigendecomposition(
 
 def read_mesh(
     mesh_config: dict[str, float | int | str],
-) -> tuple[npt.NDArray[np.float64], npt.NDArray[np.int_]]:
+) -> tuple[npt.NDArray[np.float64], npt.NDArray[np.int_]]:  # ty: ignore[invalid-return-type]
     """Read in the given mesh."""
     vertices, faces = igl.read_triangle_mesh(
         _data_path / f"meshes_polygons_{mesh_config['FILENAME']}",
     )
-    return igl.upsample(vertices, faces, number_of_subdivs=mesh_config["UPSAMPLE"])
+    return igl.upsample(vertices, faces, number_of_subdivs=mesh_config["UPSAMPLE"])  # ty: ignore[invalid-return-type]
 
 
 def _mesh_laplacian(
diff --git a/src/sleplet/_scripts/plotting_on_sphere.py b/src/sleplet/_scripts/plotting_on_sphere.py
index 1b0d9839c..2c3d405fd 100644
--- a/src/sleplet/_scripts/plotting_on_sphere.py
+++ b/src/sleplet/_scripts/plotting_on_sphere.py
@@ -330,7 +330,7 @@ def _translation_helper(
         "z": z,
         "arrowcolor": _ANNOTATION_COLOUR,
     } | _ARROW_STYLE
-    return coefficients, filename, annotation
+    return coefficients, filename, annotation  # ty: ignore[invalid-return-type]
 
 
 def _convolution_helper(
diff --git a/src/sleplet/functions/slepian.py b/src/sleplet/functions/slepian.py
index 649b2e32f..955d1c1dc 100644
--- a/src/sleplet/functions/slepian.py
+++ b/src/sleplet/functions/slepian.py
@@ -28,14 +28,14 @@ def __post_init__(self: typing_extensions.Self) -> None:
 
     def _create_name(self: typing_extensions.Self) -> str:
         order = (
-            f"_m{self.slepian.order[self.rank]}"
+            f"_m{self.slepian.order[self.rank]}"  # ty: ignore[non-subscriptable]
             if hasattr(self.slepian, "order")
             else ""
         )
         return (
             (
-                f"{self.slepian.name}{order}_rank{self.rank}"
-                f"_lam{self.slepian.eigenvalues[self.rank]:e}"
+                f"{self.slepian.name}{order}_rank{self.rank}"  # ty: ignore[possibly-missing-attribute]
+                f"_lam{self.slepian.eigenvalues[self.rank]:e}"  # ty: ignore[possibly-missing-attribute]
             )
             .replace(".", "-")
             .replace("+", "")
@@ -45,14 +45,14 @@ def _create_coefficients(
         self: typing_extensions.Self,
     ) -> npt.NDArray[np.complex128 | np.float64]:
         msg = (
-            f"Shannon number: {self.slepian.N}\n"
-            f"Eigenvalue {self.rank}: {self.slepian.eigenvalues[self.rank]:e}"
+            f"Shannon number: {self.slepian.N}\n"  # ty: ignore[possibly-missing-attribute]
+            f"Eigenvalue {self.rank}: {self.slepian.eigenvalues[self.rank]:e}"  # ty: ignore[possibly-missing-attribute]
         )
         _logger.info(msg)
         return sleplet.slepian_methods.slepian_forward(
             self.L,
             self.slepian,
-            flm=self.slepian.eigenvectors[self.rank],
+            flm=self.slepian.eigenvectors[self.rank],  # ty: ignore[possibly-missing-attribute]
         )
 
     def _set_reality(self: typing_extensions.Self) -> bool:
diff --git a/src/sleplet/functions/slepian_dirac_delta.py b/src/sleplet/functions/slepian_dirac_delta.py
index 54a4d1679..af69e0967 100644
--- a/src/sleplet/functions/slepian_dirac_delta.py
+++ b/src/sleplet/functions/slepian_dirac_delta.py
@@ -42,7 +42,7 @@ def _create_coefficients(
     def _create_name(self: typing_extensions.Self) -> str:
         return (
             f"{sleplet._string_methods._convert_camel_case_to_snake_case(self.__class__.__name__)}"
-            f"_{self.slepian.region._name_ending}"
+            f"_{self.slepian.region._name_ending}"  # ty: ignore[possibly-missing-attribute]
         )
 
     def _set_reality(self: typing_extensions.Self) -> bool:
@@ -64,7 +64,7 @@ def _compute_angles(self: typing_extensions.Self) -> None:
             Method=sleplet._vars.SAMPLING_SCHEME,
         )
         sp = ssht.inverse(
-            self.slepian.eigenvectors[0],
+            self.slepian.eigenvectors[0],  # ty: ignore[possibly-missing-attribute]
             self.L,
             Method=sleplet._vars.SAMPLING_SCHEME,
         )
diff --git a/src/sleplet/functions/slepian_identity.py b/src/sleplet/functions/slepian_identity.py
index 44dda60be..4627625bc 100644
--- a/src/sleplet/functions/slepian_identity.py
+++ b/src/sleplet/functions/slepian_identity.py
@@ -25,7 +25,7 @@ def _create_coefficients(
     def _create_name(self: typing_extensions.Self) -> str:
         return (
             f"{sleplet._string_methods._convert_camel_case_to_snake_case(self.__class__.__name__)}"
-            f"_{self.slepian.region._name_ending}"
+            f"_{self.slepian.region._name_ending}"  # ty: ignore[possibly-missing-attribute]
         )
 
     def _set_reality(self: typing_extensions.Self) -> bool:
diff --git a/src/sleplet/functions/slepian_wavelet_coefficients_africa.py b/src/sleplet/functions/slepian_wavelet_coefficients_africa.py
index a1ece446f..a13b4edb9 100644
--- a/src/sleplet/functions/slepian_wavelet_coefficients_africa.py
+++ b/src/sleplet/functions/slepian_wavelet_coefficients_africa.py
@@ -91,9 +91,9 @@ def _create_wavelet_coefficients(
         wavelet_coefficients = sleplet.wavelet_methods.slepian_wavelet_forward(
             sa.coefficients,
             wavelets,
-            self.slepian.N,
+            self.slepian.N,  # ty: ignore[possibly-missing-attribute]
         )
-        return wavelets, wavelet_coefficients
+        return wavelets, wavelet_coefficients  # ty: ignore[invalid-return-type]
 
     @pydantic.field_validator("j")
     def _check_j(
diff --git a/src/sleplet/functions/slepian_wavelet_coefficients_south_america.py b/src/sleplet/functions/slepian_wavelet_coefficients_south_america.py
index b58051c1e..b69adfe62 100644
--- a/src/sleplet/functions/slepian_wavelet_coefficients_south_america.py
+++ b/src/sleplet/functions/slepian_wavelet_coefficients_south_america.py
@@ -91,9 +91,9 @@ def _create_wavelet_coefficients(
         wavelet_coefficients = sleplet.wavelet_methods.slepian_wavelet_forward(
             sa.coefficients,
             wavelets,
-            self.slepian.N,
+            self.slepian.N,  # ty: ignore[possibly-missing-attribute]
         )
-        return wavelets, wavelet_coefficients
+        return wavelets, wavelet_coefficients  # ty: ignore[invalid-return-type]
 
     @pydantic.field_validator("j")
     def _check_j(
diff --git a/src/sleplet/functions/slepian_wavelets.py b/src/sleplet/functions/slepian_wavelets.py
index 691614afc..68ed59a4c 100644
--- a/src/sleplet/functions/slepian_wavelets.py
+++ b/src/sleplet/functions/slepian_wavelets.py
@@ -44,7 +44,7 @@ def _create_coefficients(
     def _create_name(self: typing_extensions.Self) -> str:
         return (
             f"{sleplet._string_methods._convert_camel_case_to_snake_case(self.__class__.__name__)}"
-            f"_{self.slepian.region._name_ending}"
+            f"_{self.slepian.region._name_ending}"  # ty: ignore[possibly-missing-attribute]
             f"{sleplet._string_methods.filename_args(self.B, 'B')}"
             f"{sleplet._string_methods.filename_args(self.j_min, 'jmin')}"
             f"{sleplet._string_methods.wavelet_ending(self.j_min, self.j)}"
diff --git a/src/sleplet/meshes/_mesh_slepian_decomposition.py b/src/sleplet/meshes/_mesh_slepian_decomposition.py
index 94160194d..e6bf82dd0 100644
--- a/src/sleplet/meshes/_mesh_slepian_decomposition.py
+++ b/src/sleplet/meshes/_mesh_slepian_decomposition.py
@@ -120,7 +120,7 @@ def _validate_rank(self: typing_extensions.Self, rank: int) -> None:
         if rank < 0:
             msg = "rank cannot be negative"
             raise ValueError(msg)
-        if rank >= self.mesh_slepian.mesh.number_basis_functions:
+        if rank >= self.mesh_slepian.mesh.number_basis_functions:  # ty: ignore[unsupported-operator]
             msg = (
                 "rank should be less than "
                 f"{self.mesh_slepian.mesh.number_basis_functions}"
diff --git a/src/sleplet/meshes/mesh.py b/src/sleplet/meshes/mesh.py
index 3e0d7038d..bfb41c3f5 100644
--- a/src/sleplet/meshes/mesh.py
+++ b/src/sleplet/meshes/mesh.py
@@ -70,12 +70,12 @@ def __post_init__(self: typing_extensions.Self) -> None:
             y_centre=mesh_config["CENTRE_Y"] if self.zoom else 0,
             z_centre=mesh_config["CENTRE_Z"] if self.zoom else 0,
         )
-        self._colourbar_pos = (
+        self._colourbar_pos = (  # ty: ignore[invalid-assignment]
             mesh_config["REGION_COLOURBAR_POS"]
             if self.zoom
             else mesh_config["DEFAULT_COLOURBAR_POS"]
         )
-        self.vertices, self.faces = sleplet._mesh_methods.read_mesh(mesh_config)
+        self.vertices, self.faces = sleplet._mesh_methods.read_mesh(mesh_config)  # ty: ignore[invalid-assignment]
         self.mesh_region = sleplet._mesh_methods.create_mesh_region(
             mesh_config,
             self.vertices,
diff --git a/src/sleplet/meshes/mesh_field.py b/src/sleplet/meshes/mesh_field.py
index a6b185eef..ef93bf05b 100644
--- a/src/sleplet/meshes/mesh_field.py
+++ b/src/sleplet/meshes/mesh_field.py
@@ -22,7 +22,7 @@ def _create_coefficients(
         self: typing_extensions.Self,
     ) -> npt.NDArray[np.complex128 | np.float64]:
         """Compute field on the vertices of the mesh."""
-        field = igl.per_vertex_normals(self.mesh.vertices, self.mesh.faces)[:, 1]
+        field = igl.per_vertex_normals(self.mesh.vertices, self.mesh.faces)[:, 1]  # ty: ignore[non-subscriptable]
         return sleplet.harmonic_methods.mesh_forward(self.mesh, field)
 
     def _create_name(self: typing_extensions.Self) -> str:
diff --git a/src/sleplet/meshes/mesh_harmonic_coefficients.py b/src/sleplet/meshes/mesh_harmonic_coefficients.py
index 0e2602542..fb3faa978 100644
--- a/src/sleplet/meshes/mesh_harmonic_coefficients.py
+++ b/src/sleplet/meshes/mesh_harmonic_coefficients.py
@@ -28,7 +28,7 @@ def _add_noise_to_signal(
             unnoised_coefficients = self.coefficients.copy()
             nlm = sleplet.noise._create_mesh_noise(self.coefficients, self.noise)
             snr = sleplet.noise.compute_snr(self.coefficients, nlm, "Harmonic")
-            self.coefficients = self.coefficients + nlm
+            self.coefficients = self.coefficients + nlm  # ty: ignore[invalid-assignment]
             return unnoised_coefficients, snr
         return None, None
 
diff --git a/src/sleplet/meshes/mesh_slepian_coefficients.py b/src/sleplet/meshes/mesh_slepian_coefficients.py
index 8a14276b0..6849266b7 100644
--- a/src/sleplet/meshes/mesh_slepian_coefficients.py
+++ b/src/sleplet/meshes/mesh_slepian_coefficients.py
@@ -40,7 +40,7 @@ def _add_noise_to_signal(
                 self.noise,
             )
             snr = sleplet.noise.compute_snr(self.coefficients, n_p, "Slepian")
-            self.coefficients = self.coefficients + n_p
+            self.coefficients = self.coefficients + n_p  # ty: ignore[invalid-assignment]
             return unnoised_coefficients, snr
         return None, None
 
diff --git a/src/sleplet/meshes/mesh_slepian_functions.py b/src/sleplet/meshes/mesh_slepian_functions.py
index db69badae..fda67d829 100644
--- a/src/sleplet/meshes/mesh_slepian_functions.py
+++ b/src/sleplet/meshes/mesh_slepian_functions.py
@@ -31,10 +31,10 @@ def _create_coefficients(
         """Compute field on the vertices of the mesh."""
         msg = (
             f"Slepian eigenvalue {self.rank}: "
-            f"{self.mesh_slepian.slepian_eigenvalues[self.rank]:e}",
+            f"{self.mesh_slepian.slepian_eigenvalues[self.rank]:e}",  # ty: ignore[possibly-missing-attribute]
         )
         _logger.info(msg)
-        s_p_i = self.mesh_slepian.slepian_functions[self.rank]
+        s_p_i = self.mesh_slepian.slepian_functions[self.rank]  # ty: ignore[possibly-missing-attribute]
         return sleplet.slepian_methods.slepian_mesh_forward(
             self.mesh_slepian,
             u_i=s_p_i,
@@ -44,7 +44,7 @@ def _create_name(self: typing_extensions.Self) -> str:
         return (
             (
                 f"slepian_{self.mesh.name}_rank{self.rank}_"
-                f"lam{self.mesh_slepian.slepian_eigenvalues[self.rank]:e}"
+                f"lam{self.mesh_slepian.slepian_eigenvalues[self.rank]:e}"  # ty: ignore[possibly-missing-attribute]
             )
             .replace(".", "-")
             .replace("+", "")
diff --git a/src/sleplet/meshes/mesh_slepian_wavelet_coefficients.py b/src/sleplet/meshes/mesh_slepian_wavelet_coefficients.py
index 6a3db553c..a4cad15c9 100644
--- a/src/sleplet/meshes/mesh_slepian_wavelet_coefficients.py
+++ b/src/sleplet/meshes/mesh_slepian_wavelet_coefficients.py
@@ -75,7 +75,7 @@ def _create_wavelet_coefficients(
         wavelet_coefficients = sleplet.wavelet_methods.slepian_wavelet_forward(
             smf.coefficients,
             wavelets,
-            self.mesh_slepian.N,
+            self.mesh_slepian.N,  # ty: ignore[possibly-missing-attribute]
         )
         return wavelets, wavelet_coefficients
 
diff --git a/src/sleplet/slepian/slepian_limit_lat_lon.py b/src/sleplet/slepian/slepian_limit_lat_lon.py
index 78c99a94e..4e6ddf5dc 100644
--- a/src/sleplet/slepian/slepian_limit_lat_lon.py
+++ b/src/sleplet/slepian/slepian_limit_lat_lon.py
@@ -179,7 +179,7 @@ def _slepian_matrix(
         """
         K = np.zeros((L**2, L**2), dtype=np.complex128)
 
-        for ell in numba.prange(L):
+        for ell in numba.prange(L):  # ty: ignore[not-iterable]
             for p in range(ell + 1):
                 C1 = np.sqrt((2 * ell + 1) * (2 * p + 1)) / (4 * np.pi)
 
diff --git a/tests/conftest.py b/tests/conftest.py
index d64384e34..19dc771ec 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -3,6 +3,7 @@
 import pytest
 
 import sleplet
+import sleplet._vars
 
 ARRAY_DIM = 10
 L = 16
diff --git a/tests/test_arrays.py b/tests/test_arrays.py
index dc26ba653..0fe4b6c63 100644
--- a/tests/test_arrays.py
+++ b/tests/test_arrays.py
@@ -1,6 +1,6 @@
 import numpy as np
 
-import sleplet
+import sleplet._array_methods
 
 
 def test_fill_matrix_using_hermitian_relation() -> None:
diff --git a/tests/test_bool.py b/tests/test_bool.py
index 17bdd7280..901cca761 100644
--- a/tests/test_bool.py
+++ b/tests/test_bool.py
@@ -1,6 +1,8 @@
 import numpy as np
 
 import sleplet
+import sleplet._bool_methods
+import sleplet._vars
 
 J = 2
 J_MIN = 0
diff --git a/tests/test_decomposition.py b/tests/test_decomposition.py
index 769357d06..f6fd6f4f1 100644
--- a/tests/test_decomposition.py
+++ b/tests/test_decomposition.py
@@ -3,6 +3,9 @@
 import pyssht as ssht
 
 import sleplet
+import sleplet._mask_methods
+import sleplet._vars
+import sleplet.slepian._slepian_decomposition
 
 
 def test_decompose_all_polar(
diff --git a/tests/test_harmonic.py b/tests/test_harmonic.py
index 60519edb3..b48f4a3ec 100644
--- a/tests/test_harmonic.py
+++ b/tests/test_harmonic.py
@@ -4,6 +4,7 @@
 import pyssht as ssht
 
 import sleplet
+import sleplet._vars
 
 L_LARGE = 128
 L_SMALL = 16
diff --git a/tests/test_loading_pooch.py b/tests/test_loading_pooch.py
index fa01bbb99..5f8506460 100644
--- a/tests/test_loading_pooch.py
+++ b/tests/test_loading_pooch.py
@@ -1,6 +1,6 @@
 import pathlib
 
-import sleplet
+import sleplet._data.setup_pooch
 
 
 def test_known_file_exists_on_pooch() -> None:
diff --git a/tests/test_mesh.py b/tests/test_mesh.py
index e84c3c050..cebbc8cfb 100644
--- a/tests/test_mesh.py
+++ b/tests/test_mesh.py
@@ -1,6 +1,7 @@
 import numpy as np
 
 import sleplet
+import sleplet._integration_methods
 
 
 def test_inverse_forward_transform_recovery(
diff --git a/tests/test_parallel.py b/tests/test_parallel.py
index 2f81c1d1a..28c212ce4 100644
--- a/tests/test_parallel.py
+++ b/tests/test_parallel.py
@@ -1,6 +1,6 @@
 import numpy as np
 
-import sleplet
+import sleplet._parallel_methods
 
 L_LARGE = 128
 L_SMALL = 16
diff --git a/tests/test_slepian_mesh.py b/tests/test_slepian_mesh.py
index ef61799f8..f761bf41c 100644
--- a/tests/test_slepian_mesh.py
+++ b/tests/test_slepian_mesh.py
@@ -70,15 +70,15 @@ def test_synthesis_mesh(
     wav_coeffs = sleplet.wavelet_methods.slepian_wavelet_forward(
         coefficients,
         mesh_slepian_wavelets.wavelets,
-        mesh_slepian_wavelets.mesh_slepian.N,
+        mesh_slepian_wavelets.mesh_slepian.N,  # ty: ignore[possibly-missing-attribute]
     )
     f_p = sleplet.wavelet_methods.slepian_wavelet_inverse(
         wav_coeffs,
         mesh_slepian_wavelets.wavelets,
-        mesh_slepian_wavelets.mesh_slepian.N,
+        mesh_slepian_wavelets.mesh_slepian.N,  # ty: ignore[possibly-missing-attribute]
     )
     np.testing.assert_allclose(
-        np.abs(f_p - coefficients)[: mesh_slepian_wavelets.mesh_slepian.N].mean(),
+        np.abs(f_p - coefficients)[: mesh_slepian_wavelets.mesh_slepian.N].mean(),  # ty: ignore[possibly-missing-attribute]
         0,
         atol=1e-16,
     )
diff --git a/tests/test_strings.py b/tests/test_strings.py
index 2734b1ca2..0cc12ab9e 100644
--- a/tests/test_strings.py
+++ b/tests/test_strings.py
@@ -1,6 +1,7 @@
 import numpy as np
 
 import sleplet
+import sleplet._string_methods
 
 J_MIN = 0
 PHI_0 = np.pi / 6
diff --git a/tests/test_translation.py b/tests/test_translation.py
index a1f611e07..b1a91e86a 100644
--- a/tests/test_translation.py
+++ b/tests/test_translation.py
@@ -1,9 +1,10 @@
-import hypothesis
+import hypothesis.strategies
 import numpy as np
 
 import pyssht as ssht
 
 import sleplet
+import sleplet._vars
 
 L = 128
 THETA_MAX = np.pi / 3
@@ -53,7 +54,7 @@ def test_slepian_translation_changes_max_polar(
     sdd_trans = slepian_dirac_delta_polar_cap.translate(
         slepian_dirac_delta_polar_cap._alpha,
         beta,
-        shannon=slepian_dirac_delta_polar_cap.slepian.N,
+        shannon=slepian_dirac_delta_polar_cap.slepian.N,  # ty: ignore[possibly-missing-attribute]
     )
     field = sleplet.slepian_methods.slepian_inverse(
         sdd_trans,
@@ -86,7 +87,7 @@ def test_slepian_translation_changes_max_lim_lat_lon(
     sdd_trans = slepian_dirac_delta_lim_lat_lon.translate(
         slepian_dirac_delta_lim_lat_lon._alpha,
         beta,
-        shannon=slepian_dirac_delta_lim_lat_lon.slepian.N,
+        shannon=slepian_dirac_delta_lim_lat_lon.slepian.N,  # ty: ignore[possibly-missing-attribute]
     )
     field = sleplet.slepian_methods.slepian_inverse(
         sdd_trans,
diff --git a/tests/test_wavelets.py b/tests/test_wavelets.py
index 237a96cee..9fe8beb37 100644
--- a/tests/test_wavelets.py
+++ b/tests/test_wavelets.py
@@ -24,12 +24,12 @@ def test_synthesis_polar(
     wav_coeffs = sleplet.wavelet_methods.slepian_wavelet_forward(
         coefficients,
         slepian_wavelets_polar_cap.wavelets,
-        slepian_wavelets_polar_cap.slepian.N,
+        slepian_wavelets_polar_cap.slepian.N,  # ty: ignore[possibly-missing-attribute]
     )
     f_p = sleplet.wavelet_methods.slepian_wavelet_inverse(
         wav_coeffs,
         slepian_wavelets_polar_cap.wavelets,
-        slepian_wavelets_polar_cap.slepian.N,
+        slepian_wavelets_polar_cap.slepian.N,  # ty: ignore[possibly-missing-attribute]
     )
     np.testing.assert_allclose(np.abs(f_p - coefficients).mean(), 0, atol=1e-14)
 
@@ -47,12 +47,12 @@ def test_synthesis_lim_lat_lon(
     wav_coeffs = sleplet.wavelet_methods.slepian_wavelet_forward(
         coefficients,
         slepian_wavelets_lim_lat_lon.wavelets,
-        slepian_wavelets_lim_lat_lon.slepian.N,
+        slepian_wavelets_lim_lat_lon.slepian.N,  # ty: ignore[possibly-missing-attribute]
     )
     f_p = sleplet.wavelet_methods.slepian_wavelet_inverse(
         wav_coeffs,
         slepian_wavelets_lim_lat_lon.wavelets,
-        slepian_wavelets_lim_lat_lon.slepian.N,
+        slepian_wavelets_lim_lat_lon.slepian.N,  # ty: ignore[possibly-missing-attribute]
     )
     np.testing.assert_allclose(np.abs(f_p - coefficients).mean(), 0, atol=0)
 
@@ -70,7 +70,7 @@ def test_axisymmetric_synthesis_earth() -> None:
         awc.wavelets,
     )
     np.testing.assert_allclose(
-        np.abs(flm - awc._earth.coefficients).mean(),
+        np.abs(flm - awc._earth.coefficients).mean(),  # ty: ignore[possibly-missing-attribute]
         0,
         atol=1e-13,
     )
@@ -89,7 +89,7 @@ def test_axisymmetric_synthesis_south_america() -> None:
         awc.wavelets,
     )
     np.testing.assert_allclose(
-        np.abs(flm - awc._south_america.coefficients).mean(),
+        np.abs(flm - awc._south_america.coefficients).mean(),  # ty: ignore[possibly-missing-attribute]
         0,
         atol=1e-14,
     )