diff --git a/CHANGES.rst b/CHANGES.rst
index 78aa61cc..0582181c 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -1,3 +1,11 @@
+0.20.0 (unreleased)
+-------------------
+
+other
+^^^^^
+
+- Replace ``pkg_resources`` with ``importlib.metadata``. [#478]
+
 0.19.0 (2023-09-15)
 -------------------
 
diff --git a/conftest.py b/conftest.py
deleted file mode 100644
index 5a6c2288..00000000
--- a/conftest.py
+++ /dev/null
@@ -1,8 +0,0 @@
-import pkg_resources
-
-entry_points = []
-for entry_point in pkg_resources.iter_entry_points('pytest11'):
-    entry_points.append(entry_point.name)
-
-if "asdf_schema_tester" not in entry_points:
-    pytest_plugins = ['asdf.tests.schema_tester']
diff --git a/docs/conf.py b/docs/conf.py
index 73f5592b..8e15eb80 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -33,8 +33,8 @@
     import tomllib
 except ImportError:
     import tomli as tomllib
-    
-from pkg_resources import get_distribution
+
+import importlib.metadata
 
 try:
     from sphinx_astropy.conf.v1 import *  # noqa
@@ -83,7 +83,7 @@
 # |version| and |release|, also used in various other places throughout the
 # built documents.
 
-release = get_distribution(project).version
+release = importlib.metadata.version(project)
 # for example take major/minor
 version = '.'.join(release.split('.')[:2])
 
diff --git a/gwcs/__init__.py b/gwcs/__init__.py
index 1f87f8b1..18d5c3c8 100644
--- a/gwcs/__init__.py
+++ b/gwcs/__init__.py
@@ -57,14 +57,11 @@
 
 """
 
-import sys
-from pkg_resources import get_distribution, DistributionNotFound
-if sys.version_info < (3, 6):
-    raise ImportError("GWCS supports Python versions 3.6 and above.")  # pragma: no cover
+import importlib.metadata
 
 try:
-    __version__ = get_distribution(__name__).version
-except DistributionNotFound:  # pragma: no cover
+    __version__ = importlib.metadata.version(__name__)
+except importlib.metadata.PackageNotFoundError:  # pragma: no cover
     # package is not installed
     pass  # pragma: no cover
 
diff --git a/gwcs/tests/data/__init__.py b/gwcs/tests/data/__init__.py
new file mode 100644
index 00000000..e69de29b
diff --git a/gwcs/tests/test_utils.py b/gwcs/tests/test_utils.py
index 1d4bbcbd..e69ec536 100644
--- a/gwcs/tests/test_utils.py
+++ b/gwcs/tests/test_utils.py
@@ -1,11 +1,11 @@
 # Licensed under a 3-clause BSD style license - see LICENSE.rst
+import os.path
 import numpy as np
 from astropy.io import fits
 from astropy import wcs as fitswcs
 from astropy import units as u
 from astropy import coordinates as coord
 from astropy.modeling import models
-from astropy.utils.data import get_pkg_data_filename
 from astropy.tests.helper import assert_quantity_allclose
 import pytest
 from numpy.testing import assert_allclose
@@ -13,6 +13,11 @@
 from .. import utils as gwutils
 from ..utils import UnsupportedProjectionError
 
+from . import data
+
+
+data_path = os.path.split(os.path.abspath(data.__file__))[0]
+
 
 def test_wrong_projcode():
     with pytest.raises(UnsupportedProjectionError):
@@ -26,7 +31,7 @@ def test_wrong_projcode2():
 
 
 def test_fits_transform():
-    hdr = fits.Header.fromfile(get_pkg_data_filename('data/simple_wcs2.hdr'))
+    hdr = fits.Header.fromfile(os.path.join(data_path, "simple_wcs2.hdr"))
     gw1 = gwutils.make_fitswcs_transform(hdr)
     w1 = fitswcs.WCS(hdr)
     assert_allclose(gw1(1, 2), w1.wcs_pix2world(1, 2, 0), atol=10 ** -8)
diff --git a/gwcs/tests/test_wcs.py b/gwcs/tests/test_wcs.py
index 2cde95d9..7268f392 100644
--- a/gwcs/tests/test_wcs.py
+++ b/gwcs/tests/test_wcs.py
@@ -1,16 +1,20 @@
 # Licensed under a 3-clause BSD style license - see LICENSE.rst
 import warnings
+import os.path
+
+import pytest
+
 import numpy as np
 from numpy.testing import assert_allclose, assert_equal
+
 from astropy.modeling import models
 from astropy import coordinates as coord
 from astropy.io import fits
 from astropy import units as u
-import pytest
-from astropy.utils.data import get_pkg_data_filename
 from astropy import wcs as astwcs
 from astropy.wcs import wcsapi
 from astropy.time import Time
+import asdf
 
 from .. import wcs
 from ..wcstools import (wcs_from_fiducial, grid_from_bounding_box, wcs_from_points)
@@ -18,7 +22,10 @@
 from .. import utils
 from ..utils import CoordinateFrameError
 from .utils import _gwcs_from_hst_fits_wcs
-import asdf
+from . import data
+
+
+data_path = os.path.split(os.path.abspath(data.__file__))[0]
 
 
 m1 = models.Shift(12.4) & models.Shift(-2)
@@ -378,7 +385,7 @@ def test_grid_from_bounding_box_step():
 
 def test_wcs_from_points():
     np.random.seed(0)
-    hdr = fits.Header.fromtextfile(get_pkg_data_filename("data/acs.hdr"), endcard=False)
+    hdr = fits.Header.fromtextfile(os.path.join(data_path, "acs.hdr"), endcard=False)
     with pytest.warns(astwcs.FITSFixedWarning) as caught_warnings:
         # this raises a warning unimportant for this testing the pix2world
         #   FITSFixedWarning(u'The WCS transformation has more axes (2) than
@@ -532,7 +539,7 @@ def test_high_level_api():
 
 class TestImaging(object):
     def setup_class(self):
-        hdr = fits.Header.fromtextfile(get_pkg_data_filename("data/acs.hdr"), endcard=False)
+        hdr = fits.Header.fromtextfile(os.path.join(data_path, "acs.hdr"), endcard=False)
         with pytest.warns(astwcs.FITSFixedWarning) as caught_warnings:
             # this raises a warning unimportant for this testing the pix2world
             #   FITSFixedWarning(u'The WCS transformation has more axes (2) than
@@ -640,7 +647,7 @@ def test_to_fits_sip():
     y, x = np.mgrid[:1024:10, :1024:10]
     xflat = np.ravel(x[1:-1, 1:-1])
     yflat = np.ravel(y[1:-1, 1:-1])
-    fn = get_pkg_data_filename('data/miriwcs.asdf')
+    fn = os.path.join(data_path, 'miriwcs.asdf')
     with asdf.open(fn, lazy_load=False, copy_arrays=True, ignore_missing_extensions=True) as af:
         miriwcs = af.tree['wcs']
     bounding_box = ((0, 1024), (0, 1024))
@@ -1001,7 +1008,7 @@ def test_to_fits_tab_time_cube(gwcs_cube_with_separable_time):
 
 def test_to_fits_tab_miri_image():
     # gWCS:
-    fn = get_pkg_data_filename('data/miriwcs.asdf')
+    fn = os.path.join(data_path, 'miriwcs.asdf')
     with asdf.open(fn, copy_arrays=True, lazy_load=False, ignore_missing_extensions=True) as af:
         w = af.tree['wcs']
 
@@ -1025,7 +1032,7 @@ def test_to_fits_tab_miri_image():
 
 
 def test_to_fits_tab_miri_lrs():
-    fn = get_pkg_data_filename('data/miri_lrs_wcs.asdf')
+    fn = os.path.join(data_path, 'miri_lrs_wcs.asdf')
     with asdf.open(fn, copy_arrays=True, lazy_load=False, ignore_missing_extensions=True) as af:
         w = af.tree['wcs']
 
@@ -1094,7 +1101,7 @@ def test_in_image():
 
 
 def test_iter_inv():
-    fn = get_pkg_data_filename('data/nircamwcs.asdf')
+    fn = os.path.join(data_path, 'nircamwcs.asdf')
     with asdf.open(fn, lazy_load=False, copy_arrays=False, ignore_missing_extensions=True) as af:
         w = af.tree['wcs']
     # remove analytic/user-supplied inverse:
@@ -1237,8 +1244,8 @@ def test_initialize_wcs_with_list():
 
 
 def test_sip_roundtrip():
-    hdr = fits.Header.fromtextfile(get_pkg_data_filename("data/acs.hdr"),
-                                   endcard=False)
+    hdr = fits.Header.fromtextfile(os.path.join(data_path, "acs.hdr"), endcard=False)
+
     nx = ny = 1024
     hdr['naxis'] = 2
     hdr['naxis1'] = nx
@@ -1275,7 +1282,7 @@ def test_sip_roundtrip():
 
 def test_spatial_spectral_stokes():
     """ Converts a FITS WCS to GWCS and compares results."""
-    hdr = fits.Header.fromfile(get_pkg_data_filename("data/stokes.txt"))
+    hdr = fits.Header.fromfile(os.path.join(data_path, "stokes.txt"))
     with warnings.catch_warnings():
         warnings.simplefilter("ignore", category=astwcs.FITSFixedWarning)
         aw = astwcs.WCS(hdr)
diff --git a/pyproject.toml b/pyproject.toml
index a3675460..b225a667 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -58,9 +58,8 @@ requires = [
 ]
 build-backend = "setuptools.build_meta"
 
-[tool.setuptools]
-zip-safe = false
-include-package-data = false
+[tool.setuptools.package-data]
+'gwcs.tests.data' = ["*"]
 
 [tool.setuptools.packages.find]
 namespaces = false
diff --git a/tox.ini b/tox.ini
index 93ac88e5..0418f6e8 100644
--- a/tox.ini
+++ b/tox.ini
@@ -60,7 +60,7 @@ passenv =
 set_env =
     dev: PIP_EXTRA_INDEX_URL = https://pypi.anaconda.org/scientific-python-nightly-wheels/simple
 args_are_paths = false
-change_dir = pyargs: {homedir}
+change_dir = pyargs: {env:HOME}
 extras =
     test
     alldeps: all