diff --git a/522.patch b/522.patch
new file mode 100644
index 0000000..ef4a7a9
--- /dev/null
+++ b/522.patch
@@ -0,0 +1,108 @@
+From f851356e8e56c67df96e9c7ec70e82f98bcc2efd Mon Sep 17 00:00:00 2001
+From: "Benjamin A. Beasley" <code@musicinmybrain.net>
+Date: Fri, 22 Sep 2023 11:40:47 -0400
+Subject: [PATCH 1/2] Drop the PyPI mock dependency
+
+This was only needed for Python 2.7.
+---
+ README.rst           | 6 ++----
+ dev-requirements.txt | 1 -
+ nipy/info.py         | 6 +-----
+ 3 files changed, 3 insertions(+), 10 deletions(-)
+
+diff --git a/README.rst b/README.rst
+index 9deb1a196..79fa12dea 100644
+--- a/README.rst
++++ b/README.rst
+@@ -74,10 +74,9 @@ Tests
+ =====
+ 
+ To run nipy's tests, you will need to install the nose_ Python testing
+-package.  If you are using Python 2.7, you will also need to install the mock_
+-testing package - e.g.::
++package::
+ 
+-    pip install nose mock
++    pip install nose
+ 
+ Then::
+ 
+@@ -112,5 +111,4 @@ the nipy distribution.
+ .. _ipython: http://ipython.org
+ .. _matplotlib: http://matplotlib.org
+ .. _nose: http://nose.readthedocs.org/en/latest
+-.. _mock: https://pypi.python.org/pypi/mock
+ .. _installation instructions: http://nipy.org/nipy/users/installation.html
+diff --git a/dev-requirements.txt b/dev-requirements.txt
+index aa8ad84f8..e083121ec 100644
+--- a/dev-requirements.txt
++++ b/dev-requirements.txt
+@@ -1,4 +1,3 @@
+ # Requirements for running tests
+ -r requirements.txt
+ nose3
+-mock
+diff --git a/nipy/info.py b/nipy/info.py
+index a7fe66905..d44375884 100644
+--- a/nipy/info.py
++++ b/nipy/info.py
+@@ -102,10 +102,7 @@
+ =====
+ 
+ To run nipy's tests, you will need to install the nose_ Python testing
+-package.  If you are using Python 2.7, you will also need to install the mock_
+-testing package - e.g.::
+-
+-    pip install nose mock
++package::
+ 
+ Then::
+ 
+@@ -140,7 +137,6 @@
+ .. _ipython: http://ipython.org
+ .. _matplotlib: http://matplotlib.org
+ .. _nose: http://nose.readthedocs.org/en/latest
+-.. _mock: https://pypi.python.org/pypi/mock
+ .. _six: https://six.readthedocs.io
+ .. _installation instructions: http://nipy.org/nipy/users/installation.html
+ """
+
+From 8daea8dcef620bef3959f3bbaea65576c4dfb8b4 Mon Sep 17 00:00:00 2001
+From: Ben Beasley <code@musicinmybrain.net>
+Date: Fri, 22 Sep 2023 11:49:34 -0400
+Subject: [PATCH 2/2] In documentation, recommend pip-installing nose3 instead
+ of nose
+
+Co-authored-by: Matthew Brett <matthew.brett@gmail.com>
+---
+ README.rst   | 2 +-
+ nipy/info.py | 3 +++
+ 2 files changed, 4 insertions(+), 1 deletion(-)
+
+diff --git a/README.rst b/README.rst
+index 79fa12dea..b7890158d 100644
+--- a/README.rst
++++ b/README.rst
+@@ -76,7 +76,7 @@ Tests
+ To run nipy's tests, you will need to install the nose_ Python testing
+ package::
+ 
+-    pip install nose
++    pip install nose3
+ 
+ Then::
+ 
+diff --git a/nipy/info.py b/nipy/info.py
+index d44375884..c6e5ccb23 100644
+--- a/nipy/info.py
++++ b/nipy/info.py
+@@ -104,6 +104,9 @@
+ To run nipy's tests, you will need to install the nose_ Python testing
+ package::
+ 
++    pip install nose3
++
++
+ Then::
+ 
+     python -c "import nipy; nipy.test()"
diff --git a/python-nipy.spec b/python-nipy.spec
index 787b238..68f3026 100644
--- a/python-nipy.spec
+++ b/python-nipy.spec
@@ -34,6 +34,9 @@ Source14:       nipy_tsdiffana.1
 # Upstream’s version bound is chosen for binary compatibility, which is
 # much more tightly controlled in a distribution package
 Patch:          0001-Downstream-only-allow-numpy-1.24.patch
+# Drop the PyPI mock dependency
+# https://github.com/nipy/nipy/pull/522
+Patch:          https://github.com/nipy/nipy/pull/522.patch
 
 BuildRequires:  gcc
 BuildRequires:  flexiblas-devel
@@ -47,8 +50,6 @@ BuildRequires:  python3dist(numpy)
 BuildRequires:  python3dist(matplotlib)
 
 %if %{with tests}
-# https://fedoraproject.org/wiki/Changes/DeprecateNose
-BuildRequires:  python3dist(nose)
 BuildRequires:  nipy-data
 # An indirect dependency, via nibabel.testing (for nibabel 5.x)
 BuildRequires:  python3dist(pytest)
@@ -145,9 +146,9 @@ cp -p nipy/algorithms/statistics/models/LICENSE.txt scipy-LICENSE.txt
 # Remove doc dependency version pins, which we cannot respect
 sed -r -i -e 's/(,<.*)$//' -e 's/==/>=/' doc-requirements.txt
 # We don’t have a python-nose3 package (a fork and drop-in replacement for the
-# deprecated python-nose). We also shouldn’t depend on the deprecated
-# python-mock package if we can help it.
-sed -r -i 's/^(nose3|mock)\b/# &/' dev-requirements.txt
+# deprecated python-nose). See:
+# https://fedoraproject.org/wiki/Changes/DeprecateNose
+sed -r -i 's/\bnose3\b/nose/' setup.py dev-requirements.txt
 
 # Upstream pins a numpy version in order to build forward-compatible wheels for
 # PyPI; we can’t respect the version pin, but we also don’t need it, as we only
@@ -156,7 +157,7 @@ sed -r -i 's/(numpy)==/\1>=/' pyproject.toml
 
 
 %generate_buildrequires
-%pyproject_buildrequires %{?with_doc_pdf:doc-requirements.txt}
+%pyproject_buildrequires dev-requirements.txt %{?with_doc_pdf:doc-requirements.txt}
 
 
 %build