diff --git a/doc/developer.catalog.rst b/doc/developer.catalog.rst
index a967369ba..c68ee2527 100644
--- a/doc/developer.catalog.rst
+++ b/doc/developer.catalog.rst
@@ -8,18 +8,6 @@ To do so, you will need to have the `gambit` GitHub repo cloned and be able to s
 you may wish to first review the :ref:`contributor guidelines <contributing>`.
 You'll also need to have a developer install of `pygambit` available in your Python environment, see :ref:`build-python`.
 
-The catalog module
-------------------
-
-Although the ``catalog`` directory is located at the project root outside of ``src/pygambit/``, it is installed and bundled as the ``pygambit.catalog`` subpackage.
-
-This is handled by the package build configuration in ``pyproject.toml`` under ``[tool.setuptools]``:
-
-- The ``package-dir`` mapping instructs ``setuptools`` to source the ``pygambit.catalog`` subpackage from the physical ``catalog`` directory.
-- The ``package-data`` configuration ensures all non-Python data files (like ``.efg`` and ``.nfg`` files) inside the catalog are correctly bundled during installation.
-
-As a developer, this means you will need to reinstall the package (e.g., passing ``pip install .``) for any new game files or internal catalog changes to be reflected in the ``pygambit`` module.
-
 Add new game files
 ------------------
 
@@ -58,3 +46,20 @@ Currently supported representations are:
    .. warning::
 
       Make sure you commit all changed files e.g. run ``git add --all`` before committing and pushing.
+
+
+Access from pygambit
+--------------------
+
+We keep the ``catalog`` directory at the top level of the repository because it is in principle independent
+of the Python and C++ code.  However, in order to include these games with the Python package, there is a bit
+of extra infrastructure.
+
+In ``setup.py`` we have a custom build command which first copies the contents of ``catalog/`` into the build
+directory for the Python package.  These are then exposed as data in the ``catalog_data`` directory (changing
+the name to avoid confusion or clashes with ``catalog.py``, which is responsible for accessing the catalog).
+
+The main implication is that if you are working via the Python package and you add new games to the catalog,
+you will need to rebuild and reinstall the Python extension in order to access the new games.  That is, changing
+the contents of the catalog is no different than changing any other source code in the Python package; you'll
+need to execute ``pip install .`` after the addition or change.
diff --git a/pyproject.toml b/pyproject.toml
index 71134753d..553e949fd 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -114,11 +114,11 @@ markers = [
 ]
 
 [tool.setuptools]
-packages = ["pygambit", "pygambit.catalog"]
-package-dir = { "pygambit" = "src/pygambit", "pygambit.catalog" = "catalog" }
+packages = ["pygambit"]
+package-dir = { "pygambit" = "src/pygambit" }
 
 [tool.setuptools.package-data]
-"pygambit.catalog" = ["*"]
+pygambit = ["catalog_data/**/*"]
 
 [tool.setuptools.dynamic]
 version = {file = "build_support/GAMBIT_VERSION"}
diff --git a/setup.py b/setup.py
index 4a1e82b5a..9b47eb533 100644
--- a/setup.py
+++ b/setup.py
@@ -21,10 +21,12 @@
 #
 
 import glob
+import pathlib
 import platform
+import shutil
 
 import Cython.Build
-import setuptools
+import setuptools.command.build_py
 
 cppgambit_include_dirs = ["src"]
 cppgambit_cflags = (
@@ -78,6 +80,19 @@ def solver_library_config(library_name: str, paths: list) -> tuple:
     )
 
 
+class GambitBuildPy(setuptools.command.build_py.build_py):
+    """Extend `build_py` to copy the catalog games data into the build library."""
+    def run(self) -> None:
+        super().run()
+
+        catalog_source = pathlib.Path("catalog")
+        catalog_target = pathlib.Path(self.build_lib) / "pygambit/catalog_data"
+        if catalog_target.exists():
+            shutil.rmtree(catalog_target)
+        catalog_target.mkdir(exist_ok=True, parents=True)
+        shutil.copytree(catalog_source, catalog_target, dirs_exist_ok=True)
+
+
 cppgambit_bimatrix = solver_library_config("cppgambit_bimatrix",
                                            ["linalg", "lp", "lcp", "enummixed"])
 cppgambit_liap = solver_library_config("cppgambit_liap", ["liap"])
@@ -100,6 +115,7 @@ def solver_library_config(library_name: str, paths: list) -> tuple:
 )
 
 setuptools.setup(
+    cmdclass={"build_py": GambitBuildPy},
     libraries=[cppgambit_bimatrix, cppgambit_liap, cppgambit_logit, cppgambit_simpdiv,
                cppgambit_gtracer, cppgambit_enumpoly,
                cppgambit_games, cppgambit_core],
diff --git a/catalog/__init__.py b/src/pygambit/catalog.py
similarity index 97%
rename from catalog/__init__.py
rename to src/pygambit/catalog.py
index 26104acdd..6b24f17eb 100644
--- a/catalog/__init__.py
+++ b/src/pygambit/catalog.py
@@ -6,8 +6,8 @@
 
 import pygambit as gbt
 
-# Use the full string path to the virtual package we created
-_CATALOG_RESOURCE = files(__name__)
+# Use the full string path to where the catalog data are placed in the package
+_CATALOG_RESOURCE = files("pygambit")/"catalog_data"
 
 READERS = {
     ".nfg": gbt.read_nfg,