diff --git a/charmcraft/application/commands/extensions.py b/charmcraft/application/commands/extensions.py
index 5ec436565..ba05ce786 100644
--- a/charmcraft/application/commands/extensions.py
+++ b/charmcraft/application/commands/extensions.py
@@ -21,8 +21,9 @@
 
 from craft_cli import emit
 
-from charmcraft import extensions, utils
+from charmcraft import utils
 from charmcraft.application.commands import base
+from charmcraft.extensions import registry
 
 
 class ListExtensionsCommand(base.CharmcraftCommand):
@@ -40,7 +41,7 @@ class ListExtensionsCommand(base.CharmcraftCommand):
 
     def run(self, parsed_args: argparse.Namespace):
         """Print the list of available extensions and their bases."""
-        extension_data = extensions.registry.get_extensions()
+        extension_data = registry.get_extensions()
 
         if not parsed_args.format:
             extension_data = [
diff --git a/charmcraft/store/models.py b/charmcraft/store/models.py
index a2bab62bb..f65703a5e 100644
--- a/charmcraft/store/models.py
+++ b/charmcraft/store/models.py
@@ -125,7 +125,7 @@ class Revision:
     created_at: datetime.datetime
     status: str
     errors: list[Error]
-    bases: list[Base]
+    bases: list[Base | None]
 
 
 @dataclasses.dataclass(frozen=True)
@@ -152,7 +152,7 @@ class Release:
     channel: str
     expires_at: datetime.datetime
     resources: list[Resource]
-    base: Base
+    base: Base | None
 
 
 @dataclasses.dataclass(frozen=True)
diff --git a/charmcraft/store/store.py b/charmcraft/store/store.py
index d82b75b4f..1f2e44fd0 100644
--- a/charmcraft/store/store.py
+++ b/charmcraft/store/store.py
@@ -86,7 +86,7 @@ def _build_errors(item):
 
 def _build_revision(item: dict[str, Any]) -> Revision:
     """Build a Revision from a response item."""
-    bases = [Base(**base) for base in item["bases"] if base is not None]
+    bases = [(None if base is None else Base(**base)) for base in item["bases"]]
     return Revision(
         revision=item["revision"],
         version=item["version"],
@@ -401,7 +401,7 @@ def list_releases(
                 # `datetime.datetime.fromisoformat` is available only since Py3.7
                 expires_at = parser.parse(expires_at)
             resources = [_build_resource(r) for r in item["resources"]]
-            base = Base(**item["base"])
+            base = None if item["base"] is None else Base(**item["base"])
             channel_map.append(
                 Release(
                     revision=item["revision"],
diff --git a/pyproject.toml b/pyproject.toml
index f7f1b2f07..0b1de8845 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -166,7 +166,6 @@ include = [
     "tests/integration",
 ]
 analyzeUnannotatedFunctions = false
-reportAttributeAccessIssue = "warning"
 reportIncompatibleVariableOverride = "warning"
 reportOptionalMemberAccess = "warning"
 
diff --git a/tests/integration/commands/test_init.py b/tests/integration/commands/test_init.py
index 9108a7d1e..3248e5358 100644
--- a/tests/integration/commands/test_init.py
+++ b/tests/integration/commands/test_init.py
@@ -30,7 +30,7 @@
 
 import charmcraft
 from charmcraft import errors
-from charmcraft.application import commands
+from charmcraft.application.commands import init
 from charmcraft.utils import S_IXALL
 
 with contextlib.suppress(ImportError):
@@ -97,7 +97,7 @@
 
 @pytest.fixture
 def init_command():
-    return commands.InitCommand(
+    return init.InitCommand(
         {"app": charmcraft.application.APP_METADATA, "services": None}
     )
 
@@ -107,7 +107,7 @@ def create_namespace(
     name="my-charm",
     author="J Doe",
     force=False,
-    profile=commands.init.DEFAULT_PROFILE,
+    profile=init.DEFAULT_PROFILE,
     project_dir: pathlib.Path | None = None,
 ):
     """Helper to create a valid namespace."""
@@ -269,7 +269,7 @@ def test_executable_set(new_path, init_command):
     bool(os.getenv("RUNNING_TOX")) and sys.version_info < (3, 11),
     reason="does not work inside tox in Python3.10 and below",
 )
-@pytest.mark.parametrize("profile", list(commands.init.PROFILES))
+@pytest.mark.parametrize("profile", list(init.PROFILES))
 def test_tox_success(new_path, init_command, profile):
     # fix the PYTHONPATH and PATH so the tests in the initted environment use our own
     # virtualenv libs and bins (if any), as they need them, but we're not creating a
diff --git a/tests/unit/commands/test_lifecycle.py b/tests/unit/commands/test_lifecycle.py
index 2fc1975f7..ba94a2acf 100644
--- a/tests/unit/commands/test_lifecycle.py
+++ b/tests/unit/commands/test_lifecycle.py
@@ -17,6 +17,7 @@
 
 import argparse
 import pathlib
+from unittest import mock
 
 import craft_cli
 import pytest
@@ -133,13 +134,12 @@ def test_pack_update_charm_libs_empty(
     simple_charm,
     emitter: RecordingEmitter,
     service_factory: services.ServiceFactory,
+    mock_store_anonymous_client: mock.Mock,
 ):
     simple_charm.charm_libs = [models.CharmLib(lib="my_charm.my_lib", version="0.1")]
     store_lib = Library("lib_id", "my_lib", "my_charm", 0, 1, "Lib contents", "hash")
-    service_factory.store.anonymous_client.fetch_libraries_metadata.return_value = [
-        store_lib
-    ]
-    service_factory.store.anonymous_client.get_library.return_value = store_lib
+    mock_store_anonymous_client.fetch_libraries_metadata.return_value = [store_lib]
+    mock_store_anonymous_client.get_library.return_value = store_lib
 
     pack._update_charm_libs()
 
@@ -156,16 +156,15 @@ def test_pack_update_charm_libs_no_update(
     simple_charm,
     emitter: RecordingEmitter,
     service_factory: services.ServiceFactory,
+    mock_store_anonymous_client: mock.Mock,
 ):
     simple_charm.charm_libs = [models.CharmLib(lib="my_charm.my_lib", version="0.1")]
     store_lib = Library("lib_id", "my_lib", "my_charm", 0, 1, "Lib contents", "hash")
     path = fake_project_dir / utils.get_lib_path("my_charm", "my_lib", 0)
     path.parent.mkdir(parents=True)
     path.write_text("LIBID='id'\nLIBAPI=0\nLIBPATCH=1")
-    service_factory.store.anonymous_client.fetch_libraries_metadata.return_value = [
-        store_lib
-    ]
-    service_factory.store.anonymous_client.get_library.return_value = store_lib
+    mock_store_anonymous_client.fetch_libraries_metadata.return_value = [store_lib]
+    mock_store_anonymous_client.get_library.return_value = store_lib
 
     pack._update_charm_libs()
 
@@ -181,16 +180,15 @@ def test_pack_update_charm_libs_needs_update(
     simple_charm,
     emitter: RecordingEmitter,
     service_factory: services.ServiceFactory,
+    mock_store_anonymous_client: mock.Mock,
 ):
     simple_charm.charm_libs = [models.CharmLib(lib="my_charm.my_lib", version="0.2")]
     store_lib = Library("lib_id", "my_lib", "my_charm", 0, 2, "Lib contents", "hash")
     path = fake_project_dir / utils.get_lib_path("my_charm", "my_lib", 0)
     path.parent.mkdir(parents=True)
     path.write_text("LIBID='id'\nLIBAPI=0\nLIBPATCH=1")
-    service_factory.store.anonymous_client.fetch_libraries_metadata.return_value = [
-        store_lib
-    ]
-    service_factory.store.anonymous_client.get_library.return_value = store_lib
+    mock_store_anonymous_client.fetch_libraries_metadata.return_value = [store_lib]
+    mock_store_anonymous_client.get_library.return_value = store_lib
 
     pack._update_charm_libs()
 
diff --git a/tests/unit/commands/test_store.py b/tests/unit/commands/test_store.py
index 512f5cbf7..1fe481f82 100644
--- a/tests/unit/commands/test_store.py
+++ b/tests/unit/commands/test_store.py
@@ -340,7 +340,7 @@ def test_register_bundle_warning(monkeypatch: pytest.MonkeyPatch, emitter):
 
     emitter.assert_progress(
         "\u001b[31mWARNING:\u001b[0m New bundle registration will stop working on 2024-11-01. For "
-        f"more information, see: {commands.store.BUNDLE_REGISTRATION_REMOVAL_URL}",
+        f"more information, see: {store_commands.BUNDLE_REGISTRATION_REMOVAL_URL}",
         permanent=True,
     )
     mock_store.assert_called()
@@ -358,6 +358,6 @@ def test_register_bundle_error(monkeypatch: pytest.MonkeyPatch, emitter):
 
     emitter.assert_message(
         "\u001b[31mERROR:\u001b[0m New bundle registration is discontinued as of 2024-11-01.  For "
-        f"more information, see: {commands.store.BUNDLE_REGISTRATION_REMOVAL_URL}",
+        f"more information, see: {store_commands.BUNDLE_REGISTRATION_REMOVAL_URL}",
     )
     mock_store.assert_not_called()
diff --git a/tests/unit/test_parts.py b/tests/unit/test_parts.py
index 3292b8bce..07c30ab00 100644
--- a/tests/unit/test_parts.py
+++ b/tests/unit/test_parts.py
@@ -14,6 +14,7 @@
 #
 # For further info, check https://github.com/canonical/charmcraft
 
+import pydantic
 import pytest
 from pyfakefs.fake_filesystem import FakeFilesystem
 
@@ -84,7 +85,7 @@ def test_partconfig_strict_dependencies_failure(
 
     part_config.update(MINIMAL_STRICT_CHARM)
 
-    with pytest.raises(Exception) as exc_info:
+    with pytest.raises(pydantic.ValidationError) as exc_info:
         parts.process_part_config(part_config)
 
     assert message in {e["msg"] for e in exc_info.value.errors()}