diff --git a/.coveragerc b/.coveragerc
index e497a799fc..c540edf348 100644
--- a/.coveragerc
+++ b/.coveragerc
@@ -31,8 +31,6 @@ exclude_lines =
     def __repr__
     # Ignore abstract methods
     raise NotImplementedError
-    # Ignore setuptools-less fallback
-    except pkg_resources.DistributionNotFound:
 omit =
   */gapic/*.py
   */proto/*.py
diff --git a/google/__init__.py b/google/__init__.py
deleted file mode 100644
index aa5aeae602..0000000000
--- a/google/__init__.py
+++ /dev/null
@@ -1,22 +0,0 @@
-# Copyright 2017 Google LLC
-#
-# 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.
-
-try:
-    import pkg_resources
-
-    pkg_resources.declare_namespace(__name__)
-except ImportError:
-    import pkgutil
-
-    __path__ = pkgutil.extend_path(__path__, __name__)
diff --git a/google/cloud/__init__.py b/google/cloud/__init__.py
deleted file mode 100644
index aa5aeae602..0000000000
--- a/google/cloud/__init__.py
+++ /dev/null
@@ -1,22 +0,0 @@
-# Copyright 2017 Google LLC
-#
-# 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.
-
-try:
-    import pkg_resources
-
-    pkg_resources.declare_namespace(__name__)
-except ImportError:
-    import pkgutil
-
-    __path__ = pkgutil.extend_path(__path__, __name__)
diff --git a/owlbot.py b/owlbot.py
index a125593ef3..812eadab06 100644
--- a/owlbot.py
+++ b/owlbot.py
@@ -322,20 +322,6 @@ def lint_setup_py(session):
 ''',
 )
 
-s.replace(
-    ".coveragerc",
-    """\
-    raise NotImplementedError
-omit =
-""",
-    """\
-    raise NotImplementedError
-    # Ignore setuptools-less fallback
-    except pkg_resources.DistributionNotFound:
-omit =
-""",
-)
-
 s.shell.run(["nox", "-s", "blacken"], hide_output=False)
 
 s.replace(
diff --git a/setup.py b/setup.py
index ac7e705627..930c0a1c45 100644
--- a/setup.py
+++ b/setup.py
@@ -50,15 +50,11 @@
 # Only include packages under the 'google' namespace. Do not include tests,
 # benchmarks, etc.
 packages = [
-    package for package in setuptools.find_packages() if package.startswith("google")
+    package
+    for package in setuptools.find_namespace_packages()
+    if package.startswith("google")
 ]
 
-# Determine which namespaces are needed.
-namespaces = ["google"]
-if "google.cloud" in packages:
-    namespaces.append("google.cloud")
-
-
 setuptools.setup(
     name=name,
     version=version,
@@ -85,7 +81,6 @@
     ],
     platforms="Posix; MacOS X; Windows",
     packages=packages,
-    namespace_packages=namespaces,
     install_requires=dependencies,
     extras_require=extras,
     python_requires=">=3.7",
diff --git a/tests/unit/test_packaging.py b/tests/unit/test_packaging.py
new file mode 100644
index 0000000000..966386efbf
--- /dev/null
+++ b/tests/unit/test_packaging.py
@@ -0,0 +1,37 @@
+# Copyright 2023 Google LLC
+#
+# 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.
+
+import os
+import subprocess
+import sys
+
+
+def test_namespace_package_compat(tmp_path):
+    # The ``google`` namespace package should not be masked
+    # by the presence of ``google-cloud-firestore``.
+    google = tmp_path / "google"
+    google.mkdir()
+    google.joinpath("othermod.py").write_text("")
+    env = dict(os.environ, PYTHONPATH=str(tmp_path))
+    cmd = [sys.executable, "-m", "google.othermod"]
+    subprocess.check_call(cmd, env=env)
+
+    # The ``google.cloud`` namespace package should not be masked
+    # by the presence of ``google-cloud-firestore``.
+    google_cloud = tmp_path / "google" / "cloud"
+    google_cloud.mkdir()
+    google_cloud.joinpath("othermod.py").write_text("")
+    env = dict(os.environ, PYTHONPATH=str(tmp_path))
+    cmd = [sys.executable, "-m", "google.cloud.othermod"]
+    subprocess.check_call(cmd, env=env)