diff --git a/docs/developers.rst b/docs/developers.rst
index 50dc52d..5893418 100644
--- a/docs/developers.rst
+++ b/docs/developers.rst
@@ -33,7 +33,6 @@ Information on specific functions, classes, and methods.
    api/nifreeze.data.dmri
    api/nifreeze.estimator
    api/nifreeze.exceptions
-   api/nifreeze.math
    api/nifreeze.model
    api/nifreeze.registration
    api/nifreeze.testing
diff --git a/src/nifreeze/math/__init__.py b/src/nifreeze/math/__init__.py
deleted file mode 100644
index e69de29..0000000
diff --git a/src/nifreeze/math/tests/__init__.py b/src/nifreeze/math/tests/__init__.py
deleted file mode 100644
index e69de29..0000000
diff --git a/src/nifreeze/math/tests/test_utils.py b/src/nifreeze/math/tests/test_utils.py
deleted file mode 100644
index 8461810..0000000
--- a/src/nifreeze/math/tests/test_utils.py
+++ /dev/null
@@ -1,48 +0,0 @@
-# emacs: -*- mode: python; py-indent-offset: 4; indent-tabs-mode: nil -*-
-# vi: set ft=python sts=4 ts=4 sw=4 et:
-#
-# Copyright The NiPreps Developers <nipreps@gmail.com>
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-#
-# We support and encourage derived works from this project, please read
-# about our expectations at
-#
-#     https://www.nipreps.org/community/licensing/
-#
-import numpy as np
-import pytest
-
-from nifreeze.math.utils import compute_angle, is_positive_definite
-
-
-def test_is_positive_definite():
-    matrix = np.array([[4, 1, 2], [1, 3, 1], [2, 1, 5]])
-    assert is_positive_definite(matrix)
-
-    matrix = np.array([[4, 1, 2], [1, -3, 1], [2, 1, 5]])
-    assert not is_positive_definite(matrix)
-
-
-@pytest.mark.parametrize(
-    ("v1", "v2", "closest_polarity", "expected"),
-    [
-        ([1, 0, 0], [1, 0, 0], False, 0),
-        ([1, 0, 0], [0, 1, 0], False, np.pi / 2),
-        ([1, 0, 0], [-1 / np.sqrt(2), 0, 1 / np.sqrt(2)], False, np.pi * 3 / 4),
-        ([1, 0, 0], [-1 / np.sqrt(2), 0, 1 / np.sqrt(2)], True, np.pi / 4),
-    ],
-)
-def test_compute_angle(v1, v2, closest_polarity, expected):
-    obtained = compute_angle(v1, v2, closest_polarity=closest_polarity)
-    assert np.isclose(obtained, expected)
diff --git a/src/nifreeze/math/utils.py b/src/nifreeze/math/utils.py
deleted file mode 100644
index f6bfc3a..0000000
--- a/src/nifreeze/math/utils.py
+++ /dev/null
@@ -1,89 +0,0 @@
-# emacs: -*- mode: python; py-indent-offset: 4; indent-tabs-mode: nil -*-
-# vi: set ft=python sts=4 ts=4 sw=4 et:
-#
-# Copyright The NiPreps Developers <nipreps@gmail.com>
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY kIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-#
-# We support and encourage derived works from this project, please read
-# about our expectations at
-#
-#     https://www.nipreps.org/community/licensing/
-#
-import numpy as np
-
-
-def is_positive_definite(matrix):
-    """Check whether the given matrix is positive definite. Any positive
-    definite matrix can be decomposed as the product of a lower triangular
-    matrix and its conjugate transpose by performing the Cholesky decomposition.
-    Parameters
-    ----------
-    matrix : :obj:`~numpy.ndarray`
-        The matrix to check.
-    Returns
-    -------
-    True is the matrix is positive definite; False otherwise
-    """
-
-    try:
-        # Attempt Cholesky decomposition
-        np.linalg.cholesky(matrix)
-        return True
-    except np.linalg.LinAlgError:
-        # Matrix is not positive definite
-        return False
-
-
-def compute_angle(v1, v2, closest_polarity=False):
-    """Compute the angle between two vectors.
-
-    Parameters
-    ----------
-    v1 : :obj:`~numpy.ndarray`
-        First vector.
-    v2 : :obj:`~numpy.ndarray`
-        Second vector.
-    closest_polarity : :obj:`bool`
-        ``True`` to consider the smallest of the two angles between the crossing
-         lines resulting from reversing both vectors.
-
-    Returns
-    -------
-    :obj:`float`
-        The angle between the two vectors in radians.
-
-    Examples
-    --------
-    >>> compute_angle(
-    ...     np.array((1.0, 0.0, 0.0)),
-    ...     np.array((-1.0, 0.0, 0.0)),
-    ... )  # doctest: +ELLIPSIS
-    3.1415...
-    >>> compute_angle(
-    ...     np.array((1.0, 0.0, 0.0)),
-    ...     np.array((-1.0, 0.0, 0.0)),
-    ...     closest_polarity=True,
-    ... )
-    0.0
-
-    """
-
-    cosine_angle = (v1 / np.linalg.norm(v1)) @ (v2 / np.linalg.norm(v2))
-    # Clip values to handle numerical errors
-    cosine_angle = np.clip(
-        np.abs(cosine_angle) if closest_polarity else cosine_angle,
-        -1.0,
-        1.0,
-    )
-    return np.arccos(cosine_angle)