diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 25d05c68..281618e3 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -9,7 +9,7 @@ repos:
         language: system
         require_serial: true
         pass_filenames: false
-        files: "^pyproject\\.toml|^src/.*|^tests/.*|^docs/conf.py$"
+        files: "^pyproject\\.toml|ruff\\.toml|^src/.*|^tests/.*|^docs/conf.py$"
 
       - id: format-rust
         name: Format Rust
@@ -24,7 +24,7 @@ repos:
         entry: just lint-python
         language: system
         pass_filenames: false
-        files: "^pyproject\\.toml|^src/.*|^tests/.*|^docs/conf.py$"
+        files: "^pyproject\\.toml|ruff\\.toml|^src/.*|^tests/.*|^docs/conf.py$"
 
       - id: lint-rust
         name: Lint Rust
diff --git a/pyproject.toml b/pyproject.toml
index 51daee8f..4a50f731 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -77,13 +77,3 @@ grimp = ["py.typed"]
 [tool.setuptools.packages.find]
 where = ["src"]
 namespaces = false
-
-[tool.ruff]
-line-length = 99
-exclude = [
-    'tests/assets', # These are sample packages for tests to run under - we don't want ruff to mess with them.
-    'docs/', # Documentation configuration scripts
-]
-lint.select = ["A", "C4", "E4", "E7", "E9", "F", "FLY", "FURB", "INP", "PLE", "PLR", "PT", "RUF", "SIM", "UP"]
-lint.ignore = ["C408", "PLR2004", "PLR0913", "PT006", "PT007", "SIM108", "SIM118", "SIM300"]
-lint.per-file-ignores."tests/**/*.py" = [ "RUF012", "RUF059" ]
diff --git a/ruff.toml b/ruff.toml
new file mode 100644
index 00000000..be40bf40
--- /dev/null
+++ b/ruff.toml
@@ -0,0 +1,58 @@
+line-length = 99
+exclude = [
+  'tests/assets', # These are sample packages for tests to run under - we don't want ruff to mess with them.
+  'docs/',        # Documentation configuration scripts
+]
+lint.select = [ "ALL" ]
+lint.ignore = [
+  "A005",    # [stdlib-module-shadowing]                Backward Compat.    Violated by `modulefinder.py`.
+  "ANN401",  # [any-type]                               Controversial.      We use `Any` type annotations in several places intentionally.
+  "ARG002",  # [unused-method-argument]                 Backward Compat.
+  "C408",    # [unnecessary-collection-call]            Controversial.      A micro-optimization like `dict(a=1)` -> `{"a": 1}` that hurts readability.
+  "COM812",  # [missing-trailing-comma]                 TODO enable.        Has a large diff to fix all occurrences.
+  "D1",      # [pydocstyle : Undocumented]              TODO enable.        Not a priority to have every public interface documented yet.
+  "D2",      # [pydocstyle : Whitespace issues]         TODO enable.        Has a large diff to fix all occurrences.
+  "E501",    # [line-too-long]                          Controversial.      Long comments and docstrings are sometimes clearer. The formatter already addresses most violations.
+  "FBT",     # [flake8-boolean-trap]                    Backward Compat.
+  "FIX",     # [flake8-fixme]                           Controversial.      Different projects use different conventions for FIXME/TODO comments.
+  "G004",    # [logging-f-string]                       Controversial.      A micro-optimization but hurts readability.
+  "N818",    # [error-suffix-on-exception-name]         Backward Compat.
+  "PERF203", # [try-except-in-loop]                     Controversial.      A micro-optimization but increases code complexity.
+  "PLR0913", # [too-many-arguments]                     Backward Compat.
+  "PLW1641", # [eq-without-hash]                        TODO enable.        This is low-priority, and basically an enhancement to make classes more ergonomic.
+  "PTH",     # [flake8-use-pathlib]                     Controversial.      `pathlib` adoption is subtle and might be too disruptive for this codebase. e.g. https://github.com/python-grimp/grimp/pull/289#discussion_r2636012008
+  "PT007",   # [pytest-parametrize-values-wrong-type]   TODO enable.        Inconsistent use of `@pytest.mark.parametrize("value", ("a", "b", "c"))` versus `...["a", "b", "c"])` in parameterizations.
+  "PYI025",  # [unaliased-collections-abc-set-import]   Controversial.      `collections.abc.Set` is not necessarily confused with the built-in `set`.
+  "RET504",  # [unnecessary-assign]                     Controversial.      A micro-optimization but hurts readability.
+  "RET505",  # [superfluous-else-return]                Controversial.      Explicit `else` blocks can improve readability.
+  "S101",    # [assert]                                 Controversial.       `assert` statements are sometimes appropriate for type-checking purposes.
+  "SIM108",  # [if-else-block-instead-of-if-exp]        Controversial.      Ternary/Binary in-line expressions often hurt readability.
+  "SIM118",  # [in-dict-keys]                           Controversial.      `if key in dict.keys()` sometimes has clearer intent than `if key in dict`.
+  "TC001",   # [typing-only-first-party-import]         Controversial.      This package has no/few dependencies so TYPE_CHECKING guards offer no material benefit and hurt readability.
+  "TC002",   # [typing-only-third-party-import]         Controversial.      This package has no/few dependencies so TYPE_CHECKING guards offer no material benefit and hurt readability.
+  "TC003",   # [typing-only-standard-library-import]    Controversial.      This package has no/few dependencies so TYPE_CHECKING guards offer no material benefit and hurt readability.
+  "TD",      # [missing-space-after-todo-colon]         Controversial.      Different projects use different conventions for FIXME/TODO comments.  
+  "TID252",  # [relative-imports]                       Controversial.      There are pros and cons to both relative and absolute imports in a packaging context.   
+]
+lint.per-file-ignores."tests/**/*.py" = [
+  "ANN",     # [flake8-annotations]                 Type annotations not needed in a test suite
+  "ARG",     # [flake8-unused-arguments]            Interface design doesn't need attention in a test suite
+  "B007",    # [unused-loop-control-variable]       Unused variables are common in tests    
+  "B018",    # [useless-expression]                 Unused variables are common in tests 
+  "B033",    # [duplicate-value]                    Can be deliberate in a test suite
+  "D",       # [pydocstyle]                         Docstrings not needed in a test suite
+  "EM",      # [flake8-errmsg]                      Error message style doesn't need attention in a test suite
+  "N806",    # [non-lowercase-variable-in-function] Variable naming conventions don't need attention in a test suite
+  "PLR2004", # [magic-value-comparison]             Magic values are common in tests
+  "RUF012",  # [mutable-class-default]              Type annotations not needed in a test suite    
+  "RUF059",  # [unused-unpacked-variable]           Unused variables are common in tests
+  "S",       # [flake8-bandit]                      Security patterns don't need attention in a test suite
+  "SIM300",  # [yoda-conditions]                    TODO enable.   
+  "TRY",     # [tryceratops]                        Exception handling patterns don't need attention in a test suite
+]
+lint.pydocstyle.convention = "google"
+lint.future-annotations = true
+lint.flake8-builtins.strict-checking = true
+lint.flake8-pytest-style.parametrize-names-type = "csv"
+lint.flake8-type-checking.quote-annotations = true
+lint.typing-extensions = false
diff --git a/src/grimp/__init__.py b/src/grimp/__init__.py
index e75000e1..f638d324 100644
--- a/src/grimp/__init__.py
+++ b/src/grimp/__init__.py
@@ -1,8 +1,8 @@
 __version__ = "3.14"
 
-from .application.graph import DetailedImport, ImportGraph, Import
+from .application.graph import DetailedImport, Import, ImportGraph
 from .domain.analysis import PackageDependency, Route
-from .domain.valueobjects import DirectImport, Module, Layer
+from .domain.valueobjects import DirectImport, Layer, Module
 from .main import build_graph
 
 __all__ = [
diff --git a/src/grimp/adaptors/caching.py b/src/grimp/adaptors/caching.py
index d6a10af4..d717063d 100644
--- a/src/grimp/adaptors/caching.py
+++ b/src/grimp/adaptors/caching.py
@@ -1,15 +1,17 @@
-import hashlib
+from __future__ import annotations
 
+import hashlib
 import json
 import logging
+from typing import Any
 
+from grimp import _rustgrimp as rust  # type: ignore[attr-defined]
 from grimp.application.ports.filesystem import BasicFileSystem
 from grimp.application.ports.modulefinder import FoundPackage, ModuleFile
 from grimp.domain.valueobjects import DirectImport, Module
 
 from ..application.ports.caching import Cache as AbstractCache
 from ..application.ports.caching import CacheMiss
-from grimp import _rustgrimp as rust  # type: ignore[attr-defined]
 
 logger = logging.getLogger(__name__)
 PrimitiveFormat = dict[str, list[tuple[str, int | None, str]]]
@@ -64,7 +66,7 @@ def make_data_file_unique_string(
 class Cache(AbstractCache):
     DEFAULT_CACHE_DIR = ".grimp_cache"
 
-    def __init__(self, *args, namer: type[CacheFileNamer], **kwargs) -> None:
+    def __init__(self, *args: Any, namer: type[CacheFileNamer], **kwargs: Any) -> None:
         """
         Don't instantiate Cache directly; use Cache.setup().
         """
@@ -82,7 +84,7 @@ def setup(
         exclude_type_checking_imports: bool = False,
         cache_dir: str | None = None,
         namer: type[CacheFileNamer] = CacheFileNamer,
-    ) -> "Cache":
+    ) -> Cache:
         cache = cls(
             file_system=file_system,
             found_packages=found_packages,
@@ -103,17 +105,17 @@ def cache_dir_or_default(cls, cache_dir: str | None) -> str:
     def read_imports(self, module_file: ModuleFile) -> set[DirectImport]:
         try:
             cached_mtime = self._mtime_map[module_file.module.name]
-        except KeyError:
-            raise CacheMiss
+        except KeyError as exc:
+            raise CacheMiss from exc
         if cached_mtime != module_file.mtime:
             raise CacheMiss
 
         try:
             return self._data_map[module_file.module]
-        except KeyError:
+        except KeyError as exc:
             # While we would expect the module to be in here,
             # there's no point in crashing if, for some reason, it's not.
-            raise CacheMiss
+            raise CacheMiss from exc
 
     def write(
         self,
@@ -170,12 +172,13 @@ def _read_mtime_map_file(self, found_package: FoundPackage) -> dict[str, float]:
             return {}
         try:
             deserialized = json.loads(serialized)
-            logger.info(f"Used cache meta file {meta_cache_filename}.")
-            return deserialized
         except json.JSONDecodeError:
             logger.warning(f"Could not use corrupt cache file {meta_cache_filename}.")
             return {}
 
+        logger.info(f"Used cache meta file {meta_cache_filename}.")
+        return deserialized
+
     def _build_data_map(self) -> None:
         self._data_map = self._read_data_map_file()
 
diff --git a/src/grimp/adaptors/filesystem.py b/src/grimp/adaptors/filesystem.py
index cded5eab..0a396cee 100644
--- a/src/grimp/adaptors/filesystem.py
+++ b/src/grimp/adaptors/filesystem.py
@@ -1,9 +1,11 @@
+from __future__ import annotations
+
 import os
 import tokenize
 from collections.abc import Iterator
 
-from grimp.application.ports.filesystem import AbstractFileSystem, BasicFileSystem
 from grimp import _rustgrimp as rust  # type: ignore[attr-defined]
+from grimp.application.ports.filesystem import AbstractFileSystem, BasicFileSystem
 
 
 class FileSystem(AbstractFileSystem):
diff --git a/src/grimp/adaptors/modulefinder.py b/src/grimp/adaptors/modulefinder.py
index 2fae2956..00f77374 100644
--- a/src/grimp/adaptors/modulefinder.py
+++ b/src/grimp/adaptors/modulefinder.py
@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import logging
 from collections.abc import Iterable, Set
 
@@ -79,9 +81,11 @@ def _get_python_files_and_namespace_dirs_inside_package(
             for d in dirs_to_remove:
                 dirs.remove(d)
 
-            for filename in files:
-                if self._is_python_file(filename, dirpath):
-                    python_files.append(self.file_system.join(dirpath, filename))
+            python_files.extend(
+                self.file_system.join(dirpath, filename)
+                for filename in files
+                if self._is_python_file(filename, dirpath)
+            )
 
         namespace_dirs = self._determine_namespace_dirs(candidate_namespace_dirs, python_files)
         return python_files, namespace_dirs
@@ -112,9 +116,11 @@ def _is_python_file(self, filename: str, dirpath: str) -> bool:
         Files with extra dots in the name won't be treated as Python files.
 
         Args:
-            filename (str): the filename, excluding the path.
+            filename: the filename, excluding the path.
+            dirpath: the directory path containing the file.
+
         Returns:
-            bool: whether it's a Python file.
+            Whether it's a Python file.
         """
         # Ignore hidden files.
         if filename.startswith("."):
@@ -138,12 +144,13 @@ def _module_name_from_filename(
     ) -> str:
         """
         Args:
-            package_name (string) - the importable name of the top level package. Could
+            package_name: the importable name of the top level package. Could
                 be namespaced.
-            filename_and_path (string) - the full name of the Python file.
-            package_directory (string) - the full path of the top level Python package directory.
-         Returns:
-            Absolute module name for importing (string).
+            filename_and_path: the full name of the Python file.
+            package_directory: the full path of the top level Python package directory.
+
+        Returns:
+            Absolute module name for importing.
         """
         internal_filename_and_path = filename_and_path[len(package_directory) :]
         internal_filename_and_path_without_extension = internal_filename_and_path[1:-3]
@@ -160,11 +167,12 @@ def _namespace_from_dir(
     ) -> str:
         """
         Args:
-            package_name (string) - the importable name of the top level package. Could
+            package_name: the importable name of the top level package. Could
                 be namespaced.
-            namespace_dir (string) - the full name of the namespace directory.
-            package_directory (string) - the full path of the top level Python package directory.
-         Returns:
+            namespace_dir: the full name of the namespace directory.
+            package_directory: the full path of the top level Python package directory.
+
+        Returns:
             Absolute module name for importing (string).
         """
         parent_of_package_directory = package_directory[: -len(package_name)]
diff --git a/src/grimp/adaptors/packagefinder.py b/src/grimp/adaptors/packagefinder.py
index 09d459f5..7da528dd 100644
--- a/src/grimp/adaptors/packagefinder.py
+++ b/src/grimp/adaptors/packagefinder.py
@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import importlib.util
 import logging
 import sys
@@ -19,7 +21,8 @@ def determine_package_directories(
         spec = importlib.util.find_spec(package_name)
         if not spec:
             logger.debug(f"sys.path: {sys.path}")
-            raise ValueError(f"Could not find package '{package_name}' in your Python path.")
+            msg = f"Could not find package '{package_name}' in your Python path."
+            raise ValueError(msg)
 
         if (
             spec.has_location
diff --git a/src/grimp/application/config.py b/src/grimp/application/config.py
index 9a7879c6..6bec409e 100644
--- a/src/grimp/application/config.py
+++ b/src/grimp/application/config.py
@@ -1,19 +1,21 @@
+from __future__ import annotations
+
 from typing import Any
 
 
 class Settings:
-    def __init__(self):
-        self._config = {}
+    def __init__(self) -> None:
+        self._config: dict[str, Any] = {}
 
-    def configure(self, **config_dict: Any):
+    def configure(self, **config_dict: Any) -> None:
         self._config.update(config_dict)
 
-    def __getattr__(self, name):
+    def __getattr__(self, name: str) -> Any:
         if name[:2] != "__":
             return self._config[name]
-        return super().__getattr__(name)
+        return super().__getattribute__(name)
 
-    def copy(self) -> "Settings":
+    def copy(self) -> Settings:
         new_instance = self.__class__()
         new_instance.configure(**self._config)
         return new_instance
diff --git a/src/grimp/application/graph.py b/src/grimp/application/graph.py
index 0847511c..21533f18 100644
--- a/src/grimp/application/graph.py
+++ b/src/grimp/application/graph.py
@@ -1,14 +1,16 @@
 from __future__ import annotations
-from typing import TypedDict
+
 from collections.abc import Sequence
+from typing import TypedDict
+
+from grimp import _rustgrimp as rust  # type: ignore[attr-defined]
 from grimp.domain.analysis import PackageDependency, Route
 from grimp.domain.valueobjects import Layer
-from grimp import _rustgrimp as rust  # type: ignore[attr-defined]
 from grimp.exceptions import (
+    InvalidImportExpression,
+    InvalidModuleExpression,
     ModuleNotPresent,
     NoSuchContainer,
-    InvalidModuleExpression,
-    InvalidImportExpression,
 )
 
 
@@ -53,24 +55,20 @@ def find_matching_modules(self, expression: str) -> set[str]:
         """
         Find all modules matching the passed expression.
 
+        A module expression is used to refer to sets of modules.
+        - ``*`` stands in for a module name, without including subpackages.
+        - ``**`` includes subpackages too.
+
         Args:
             expression: A module expression used for matching.
+
         Returns:
             A set of module names matching the expression.
+
         Raises:
             InvalidModuleExpression if the passed expression is invalid.
 
-        Module Expressions
-        ==================
-
-        A module expression is used to refer to sets of modules.
-
-        - ``*`` stands in for a module name, without including subpackages.
-        - ``**`` includes subpackages too.
-
-        Examples
-        --------
-
+        Examples:
         - ``mypackage.foo``:  matches ``mypackage.foo`` exactly.
         - ``mypackage.*``:  matches ``mypackage.foo`` but not ``mypackage.foo.bar``.
         - ``mypackage.*.baz``: matches ``mypackage.foo.baz`` but not ``mypackage.foo.bar.baz``.
@@ -82,8 +80,8 @@ def find_matching_modules(self, expression: str) -> set[str]:
         """
         try:
             return self._rustgraph.find_matching_modules(expression)
-        except rust.InvalidModuleExpression as e:
-            raise InvalidModuleExpression(str(e)) from e
+        except rust.InvalidModuleExpression as exc:
+            raise InvalidModuleExpression(str(exc)) from exc
 
     def add_module(self, module: str, is_squashed: bool = False) -> None:
         """
@@ -118,7 +116,8 @@ def squash_module(self, module: str) -> None:
         """
         self._cached_modules = None
         if not self._rustgraph.contains_module(module):
-            raise ModuleNotPresent(f'"{module}" not present in the graph.')
+            msg = f'"{module}" not present in the graph.'
+            raise ModuleNotPresent(msg)
         self._rustgraph.squash_module(module)
 
     def is_module_squashed(self, module: str) -> bool:
@@ -128,7 +127,8 @@ def is_module_squashed(self, module: str) -> bool:
         If the module is not present in the graph, grimp.exceptions.ModuleNotPresent will be raised.
         """
         if not self._rustgraph.contains_module(module):
-            raise ModuleNotPresent(f'"{module}" not present in the graph.')
+            msg = f'"{module}" not present in the graph.'
+            raise ModuleNotPresent(msg)
         return self._rustgraph.is_module_squashed(module)
 
     def add_import(
@@ -178,7 +178,8 @@ def find_children(self, module: str) -> set[str]:
         # It doesn't make sense to find the children of a squashed module, as we don't store
         # the children in the graph.
         if self.is_module_squashed(module):
-            raise ValueError("Cannot find children of a squashed module.")
+            msg = "Cannot find children of a squashed module."
+            raise ValueError(msg)
         return self._rustgraph.find_children(module)
 
     def find_descendants(self, module: str) -> set[str]:
@@ -192,7 +193,8 @@ def find_descendants(self, module: str) -> set[str]:
         # It doesn't make sense to find the descendants of a squashed module, as we don't store
         # the descendants in the graph.
         if self.is_module_squashed(module):
-            raise ValueError("Cannot find descendants of a squashed module.")
+            msg = "Cannot find descendants of a squashed module."
+            raise ValueError(msg)
         return self._rustgraph.find_descendants(module)
 
     # Direct imports
@@ -225,7 +227,9 @@ def find_modules_that_directly_import(self, module: str) -> set[str]:
 
     def get_import_details(self, *, importer: str, imported: str) -> list[DetailedImport]:
         """
-        Return available metadata relating to the direct imports between two modules, in the form:
+        Return available metadata relating to the direct imports between two modules.
+
+        This returns a list of dictionaries in the following form:
         [
             {
                 'importer': 'mypackage.importer',
@@ -265,10 +269,12 @@ def find_matching_direct_imports(self, import_expression: str) -> list[Import]:
             import_expression: An expression used for matching importing modules, in the form
                 "importer_expression -> imported_expression", where both expressions are
                 module expressions.
+
         Returns:
             A list of direct imports matching the expressions, ordered alphabetically by importer,
             then imported.
             (We return a list rather than a set purely because dictionaries aren't hashable.)
+
         Raises:
             InvalidImportExpression if either of the passed expressions are invalid.
 
@@ -276,17 +282,17 @@ def find_matching_direct_imports(self, import_expression: str) -> list[Import]:
         """
         try:
             importer_expression, imported_expression = import_expression.split(" -> ")
-        except ValueError:
-            raise InvalidImportExpression(f"{import_expression} is not a valid import expression.")
+        except ValueError as exc:
+            msg = f"{import_expression} is not a valid import expression."
+            raise InvalidImportExpression(msg) from exc
 
         try:
             return self._rustgraph.find_matching_direct_imports(
                 importer_expression=importer_expression, imported_expression=imported_expression
             )
-        except rust.InvalidModuleExpression as e:
-            raise InvalidImportExpression(
-                f"{import_expression} is not a valid import expression."
-            ) from e
+        except rust.InvalidModuleExpression as exc:
+            msg = f"{import_expression} is not a valid import expression."
+            raise InvalidImportExpression(msg) from exc
 
     # Indirect imports
     # ----------------
@@ -295,6 +301,7 @@ def find_downstream_modules(self, module: str, as_package: bool = False) -> set[
         """
         Return a set of the names of all the modules that import (even indirectly) the
         supplied module name.
+
         Args:
             module:        The absolute name of the upstream Module.
             as_package: Whether or not to treat the supplied module as an individual module,
@@ -303,7 +310,6 @@ def find_downstream_modules(self, module: str, as_package: bool = False) -> set[
                            modules *external* to the subpackage, and won't include modules within
                            the subpackage.
         Usage:
-
             # Returns the modules downstream of mypackage.foo.
             import_graph.find_downstream_modules('mypackage.foo')
 
@@ -346,7 +352,8 @@ def find_shortest_chain(
         """
         for module in (importer, imported):
             if not self._rustgraph.contains_module(module):
-                raise ValueError(f"Module {module} is not present in the graph.")
+                msg = f"Module {module} is not present in the graph."
+                raise ValueError(msg)
 
         chain = self._rustgraph.find_shortest_chain(importer, imported, as_packages)
         return tuple(chain) if chain else None
@@ -410,22 +417,23 @@ def find_illegal_dependencies_for_layers(
         included in the import chain. For example, given the layers high -> mid (closed) -> low then
         all import chains from high -> low must go via mid.
 
-        Arguments:
-
-        - layers:     A sequence, each element of which consists either of a `Layer`, the name
-                      of a layer module or a set of sibling modules. If containers
-                      are also specified, then these names must be relative to the container.
-                      The order is from higher to lower level layers. Any layers that don't
-                      exist in the graph will be ignored.
-        - containers: The parent modules of the layers, as absolute names that you could import,
-                      such as "mypackage.foo". (Optional.)
+        Args:
+            layers: A sequence, each element of which consists either of a `Layer`, the name
+                    of a layer module or a set of sibling modules. If containers
+                    are also specified, then these names must be relative to the container.
+                    The order is from higher to lower level layers. Any layers that don't
+                    exist in the graph will be ignored.
+            containers: The parent modules of the layers, as absolute names that you could import,
+                        such as "mypackage.foo". (Optional.)
 
-        Returns the illegal dependencies in the form of a set of PackageDependency objects.
-        Each package dependency is for a different permutation of two layers for which there
-        is a violation, and contains information about the illegal chains of imports from the
-        lower layer (the 'upstream') to the higher layer (the 'downstream').
+        Returns:
+            The illegal dependencies in the form of a set of PackageDependency objects.
+            Each package dependency is for a different permutation of two layers for which there
+            is a violation, and contains information about the illegal chains of imports from the
+            lower layer (the 'upstream') to the higher layer (the 'downstream').
 
-        Raises NoSuchContainer if the container is not a module in the graph.
+        Raises:
+            NoSuchContainer: if the container is not a module in the graph.
         """
         layers = _parse_layers(layers)
         try:
@@ -441,7 +449,7 @@ def find_illegal_dependencies_for_layers(
                 containers=set(containers) if containers else set(),
             )
         except rust.NoSuchContainer as e:
-            raise NoSuchContainer(str(e))
+            raise NoSuchContainer(str(e)) from None
 
         return _dependencies_from_tuple(result)
 
@@ -450,7 +458,8 @@ def nominate_cycle_breakers(self, package: str) -> set[ImportTuple]:
         Identify a set of imports that, if removed, would make the package locally acyclic.
         """
         if not self._rustgraph.contains_module(package):
-            raise ModuleNotPresent(f'"{package}" not present in the graph.')
+            msg = f'"{package}" not present in the graph.'
+            raise ModuleNotPresent(msg)
         return self._rustgraph.nominate_cycle_breakers(package)
 
     # Dunder methods
@@ -458,8 +467,9 @@ def nominate_cycle_breakers(self, package: str) -> set[ImportTuple]:
 
     def __repr__(self) -> str:
         """
-        Display the instance in one of the following ways:
+        Display the instance.
 
+        This can be one of the following ways:
             <ImportGraph: empty>
             <ImportGraph: 'one', 'two', 'three', 'four', 'five'>
             <ImportGraph: 'one', 'two', 'three', 'four', 'five', ...>
diff --git a/src/grimp/application/ports/caching.py b/src/grimp/application/ports/caching.py
index c271ddd4..46f10997 100644
--- a/src/grimp/application/ports/caching.py
+++ b/src/grimp/application/ports/caching.py
@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 from grimp.application.ports.modulefinder import FoundPackage, ModuleFile
 from grimp.domain.valueobjects import DirectImport, Module
 
@@ -35,7 +37,7 @@ def setup(
         include_external_packages: bool,
         exclude_type_checking_imports: bool = False,
         cache_dir: str | None = None,
-    ) -> "Cache":
+    ) -> Cache:
         cache = cls(
             file_system=file_system,
             found_packages=found_packages,
diff --git a/src/grimp/application/ports/filesystem.py b/src/grimp/application/ports/filesystem.py
index 268b1efe..92e5504c 100644
--- a/src/grimp/application/ports/filesystem.py
+++ b/src/grimp/application/ports/filesystem.py
@@ -1,4 +1,5 @@
 from __future__ import annotations
+
 import abc
 from collections.abc import Iterator
 from typing import Protocol
@@ -12,7 +13,7 @@ class AbstractFileSystem(abc.ABC):
     @property
     @abc.abstractmethod
     def sep(self) -> str:
-        """
+        r"""
         Return the file separator for the FileSystem.
 
         E.G. '/' for UNIX systems and '\\' for Windows systems
diff --git a/src/grimp/application/ports/modulefinder.py b/src/grimp/application/ports/modulefinder.py
index 779e6b7e..1d59f936 100644
--- a/src/grimp/application/ports/modulefinder.py
+++ b/src/grimp/application/ports/modulefinder.py
@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import abc
 from collections.abc import Set
 from dataclasses import dataclass
diff --git a/src/grimp/application/ports/packagefinder.py b/src/grimp/application/ports/packagefinder.py
index 30b6d0ed..317f5318 100644
--- a/src/grimp/application/ports/packagefinder.py
+++ b/src/grimp/application/ports/packagefinder.py
@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import abc
 
 from .filesystem import AbstractFileSystem
diff --git a/src/grimp/application/scanning.py b/src/grimp/application/scanning.py
index 09eab3c8..47b85506 100644
--- a/src/grimp/application/scanning.py
+++ b/src/grimp/application/scanning.py
@@ -1,10 +1,12 @@
+from __future__ import annotations
+
 from collections.abc import Collection
 
 from grimp import _rustgrimp as rust  # type: ignore[attr-defined]
-from grimp.domain.valueobjects import DirectImport, Module
 from grimp.application.config import settings
 from grimp.application.ports.filesystem import AbstractFileSystem
-from grimp.application.ports.modulefinder import ModuleFile, FoundPackage
+from grimp.application.ports.modulefinder import FoundPackage, ModuleFile
+from grimp.domain.valueobjects import DirectImport, Module
 
 
 def scan_imports(
diff --git a/src/grimp/application/usecases.py b/src/grimp/application/usecases.py
index baa30b42..1e2fec61 100644
--- a/src/grimp/application/usecases.py
+++ b/src/grimp/application/usecases.py
@@ -2,18 +2,20 @@
 Use cases handle application logic.
 """
 
-from typing import cast
+from __future__ import annotations
+
 import itertools
-from collections.abc import Sequence, Iterable
+from collections.abc import Iterable, Sequence
+from typing import cast
 
-from .scanning import scan_imports
+from ..application.graph import ImportGraph
 from ..application.ports import caching
 from ..application.ports.filesystem import AbstractFileSystem, BasicFileSystem
-from ..application.graph import ImportGraph
 from ..application.ports.modulefinder import AbstractModuleFinder, FoundPackage, ModuleFile
 from ..application.ports.packagefinder import AbstractPackageFinder
 from ..domain.valueobjects import DirectImport, Module
 from .config import settings
+from .scanning import scan_imports
 
 
 class NotSupplied:
@@ -21,8 +23,8 @@ class NotSupplied:
 
 
 def build_graph(
-    package_name,
-    *additional_package_names,
+    package_name: str,
+    *additional_package_names: str,
     include_external_packages: bool = False,
     exclude_type_checking_imports: bool = False,
     cache_dir: str | type[NotSupplied] | None = NotSupplied,
@@ -31,13 +33,13 @@ def build_graph(
     Build and return an import graph for the supplied package name(s).
 
     Args:
-        - package_name: the name of the top level package for which to build the graph.
-        - additional_package_names: tuple of additional packages to build the graph from.
-        - include_external_packages: whether to include any external packages in the graph.
-        - exclude_type_checking_imports: whether to exclude imports made in type checking guards.
-        - cache_dir: The directory to use for caching the graph.
-    Examples:
+        package_name: the name of the top level package for which to build the graph.
+        additional_package_names: tuple of additional packages to build the graph from.
+        include_external_packages: whether to include any external packages in the graph.
+        exclude_type_checking_imports: whether to exclude imports made in type checking guards.
+        cache_dir: The directory to use for caching the graph.
 
+    Examples:
         # Single package.
         graph = build_graph("mypackage")
         graph = build_graph("mypackage", include_external_packages=True)
@@ -99,13 +101,15 @@ def _validate_package_names_are_strings(
 ) -> Sequence[str]:
     for name in package_names:
         if not isinstance(name, str):
-            raise TypeError(f"Package names must be strings, got {name.__class__.__name__}.")
-    return cast(Sequence[str], package_names)
+            msg = f"Package names must be strings, got {name.__class__.__name__}."
+            raise TypeError(msg)
+    return cast("Sequence[str]", package_names)
 
 
 def _scan_packages(
     found_packages: set[FoundPackage],
     file_system: BasicFileSystem,
+    *,
     include_external_packages: bool,
     exclude_type_checking_imports: bool,
     cache_dir: str | type[NotSupplied] | None,
diff --git a/src/grimp/domain/analysis.py b/src/grimp/domain/analysis.py
index 88a54179..0e03011a 100644
--- a/src/grimp/domain/analysis.py
+++ b/src/grimp/domain/analysis.py
@@ -1,7 +1,7 @@
 from __future__ import annotations
 
-from dataclasses import dataclass
 from collections.abc import Iterable, Sequence
+from dataclasses import dataclass
 
 
 @dataclass(frozen=True, order=True)
@@ -32,7 +32,6 @@ def new(
         Optional constructor for a Route with more permissive input types.
 
         Example:
-
             Route.new(
                 heads={"foo"},
                 middle=["bar", "baz"],
@@ -52,7 +51,6 @@ def single_chained(cls, *modules: str) -> Route:
         Optional constructor for a Route with a single chain.
 
         Example:
-
             Route.single_chained("foo", "bar", "baz")
 
         """
@@ -89,7 +87,6 @@ def new(
         Optional constructor for a PackageDependency with more permissive input types.
 
         Example:
-
             PackageDependency.new(
                 importer="foo",
                 imported="bar",
diff --git a/src/grimp/domain/valueobjects.py b/src/grimp/domain/valueobjects.py
index 66bb60fb..bdc050fb 100644
--- a/src/grimp/domain/valueobjects.py
+++ b/src/grimp/domain/valueobjects.py
@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 from dataclasses import dataclass
 
 
@@ -18,27 +20,28 @@ def package_name(self) -> str:
         return self.name.split(".")[0]
 
     @property
-    def root(self) -> "Module":
+    def root(self) -> Module:
         """
         The root package.
         """
         return Module(self.package_name)
 
     @property
-    def parent(self) -> "Module":
+    def parent(self) -> Module:
         components = self.name.split(".")
         if len(components) == 1:
-            raise ValueError("Module has no parent.")
+            msg = "Module has no parent."
+            raise ValueError(msg)
         return Module(".".join(components[:-1]))
 
-    def is_child_of(self, module: "Module") -> bool:
+    def is_child_of(self, module: Module) -> bool:
         try:
             return module == self.parent
         except ValueError:
             # If this module has no parent, then it cannot be a child of the supplied module.
             return False
 
-    def is_descendant_of(self, module: "Module") -> bool:
+    def is_descendant_of(self, module: Module) -> bool:
         return self.name.startswith(f"{module.name}.")
 
 
diff --git a/src/grimp/exceptions.py b/src/grimp/exceptions.py
index 15112530..db5c70a9 100644
--- a/src/grimp/exceptions.py
+++ b/src/grimp/exceptions.py
@@ -1,9 +1,18 @@
+from __future__ import annotations
+
 import warnings
+from typing import Any
 
 
-def __getattr__(name: str):
+def __getattr__(name: str) -> Any:
     if name == "NamespacePackageEncountered":
-        _NamespacePackageEncountered._warn_deprecated()
+        warnings.warn(
+            f"{_NamespacePackageEncountered.__name__} is deprecated; graphs can now be built from "
+            f"namespace packages starting from Grimp 3.14. This exception will not be "
+            f"raised by Grimp anymore, and will be removed in Grimp 3.16.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
         return _NamespacePackageEncountered
     raise AttributeError
 
@@ -31,16 +40,8 @@ class _NamespacePackageEncountered(GrimpException):
     Deprecated.
     """
 
+    # See `__getattr__` above.
     # https://github.com/python-grimp/grimp/issues/272
-    @staticmethod
-    def _warn_deprecated():
-        warnings.warn(
-            "NamespacePackageEncountered is deprecated; graphs can now be built from "
-            "namespace packages starting from Grimp 3.14. This exception will not be "
-            "raised by Grimp anymore, and will be removed in Grimp 3.16.",
-            DeprecationWarning,
-            stacklevel=2,
-        )
 
 
 class NotATopLevelModule(GrimpException):
@@ -65,19 +66,22 @@ def __init__(self, filename: str, lineno: int | None, text: str | None) -> None:
         self.lineno = lineno
         self.text = text
 
-    def __str__(self):
+    def __str__(self) -> str:
         lineno = self.lineno or "?"
         text = self.text or "<unavailable>"
         return f"Syntax error in {self.filename}, line {lineno}: {text}"
 
-    def __eq__(self, other):
+    def __eq__(self, other: object) -> bool:
+        if not isinstance(other, SourceSyntaxError):
+            return NotImplemented
+
         return (self.filename, self.lineno, self.text) == (
             other.filename,
             other.lineno,
             other.text,
         )
 
-    def __reduce__(self):
+    def __reduce__(self) -> tuple[type[SourceSyntaxError], tuple[str, int | None, str | None]]:
         # Implement __reduce__ to make this exception pickleable,
         # allowing it to be sent between processes.
         return SourceSyntaxError, (self.filename, self.lineno, self.text)
diff --git a/src/grimp/main.py b/src/grimp/main.py
index 45a297a0..57d02f47 100644
--- a/src/grimp/main.py
+++ b/src/grimp/main.py
@@ -2,11 +2,11 @@
 
 from .adaptors.caching import Cache
 from .adaptors.filesystem import FileSystem
-from .application.graph import ImportGraph
 from .adaptors.modulefinder import ModuleFinder
 from .adaptors.packagefinder import ImportLibPackageFinder
 from .adaptors.timing import SystemClockTimer
 from .application.config import settings
+from .application.graph import ImportGraph
 from .application.usecases import build_graph
 
 settings.configure(
diff --git a/tests/adaptors/filesystem.py b/tests/adaptors/filesystem.py
index 4903ca11..db471f68 100644
--- a/tests/adaptors/filesystem.py
+++ b/tests/adaptors/filesystem.py
@@ -1,10 +1,12 @@
-from typing import Any
+from __future__ import annotations
+
 from collections.abc import Generator
+from typing import Any
 
 import yaml
 
-from grimp.application.ports.filesystem import AbstractFileSystem, BasicFileSystem
 from grimp import _rustgrimp as rust  # type: ignore[attr-defined]
+from grimp.application.ports.filesystem import AbstractFileSystem, BasicFileSystem
 
 DEFAULT_MTIME = 10000.0
 
diff --git a/tests/adaptors/modulefinder.py b/tests/adaptors/modulefinder.py
index 423fb3db..50acdd2c 100644
--- a/tests/adaptors/modulefinder.py
+++ b/tests/adaptors/modulefinder.py
@@ -1,5 +1,7 @@
-from grimp.application.ports.modulefinder import AbstractModuleFinder, FoundPackage, ModuleFile
+from __future__ import annotations
+
 from grimp.application.ports.filesystem import AbstractFileSystem
+from grimp.application.ports.modulefinder import AbstractModuleFinder, FoundPackage, ModuleFile
 
 
 class BaseFakeModuleFinder(AbstractModuleFinder):
diff --git a/tests/adaptors/packagefinder.py b/tests/adaptors/packagefinder.py
index 5740677d..81d1b70b 100644
--- a/tests/adaptors/packagefinder.py
+++ b/tests/adaptors/packagefinder.py
@@ -1,7 +1,9 @@
+from __future__ import annotations
+
 from collections.abc import Mapping
-from grimp.application.ports.packagefinder import AbstractPackageFinder
 
 from grimp.application.ports.filesystem import AbstractFileSystem
+from grimp.application.ports.packagefinder import AbstractPackageFinder
 
 
 class BaseFakePackageFinder(AbstractPackageFinder):
diff --git a/tests/benchmarking/test_benchmarking.py b/tests/benchmarking/test_benchmarking.py
index e5ce4167..abcf0d16 100644
--- a/tests/benchmarking/test_benchmarking.py
+++ b/tests/benchmarking/test_benchmarking.py
@@ -1,14 +1,15 @@
-import uuid
-import random
-import pytest
-import json
 import importlib
+import json
+import random
+import uuid
+from copy import deepcopy
 from pathlib import Path
 
-from grimp.application.graph import ImportGraph
-from grimp import PackageDependency, Route
+import pytest
+
 import grimp
-from copy import deepcopy
+from grimp import PackageDependency, Route
+from grimp.application.graph import ImportGraph
 
 
 @pytest.fixture(scope="module")
@@ -354,7 +355,7 @@ def test_build_django_from_cache_a_few_misses(benchmark, number_of_misses: int):
     grimp.build_graph("django")
     # Add some modules which won't be in the cache.
     # (Use some real python, which will take time to parse.)
-    django_path = Path(importlib.util.find_spec("django").origin).parent  # type: ignore
+    django_path = Path(importlib.util.find_spec("django").origin).parent  # type: ignore[arg-type,union-attr]
     module_to_copy = django_path / "forms" / "forms.py"
     module_contents = module_to_copy.read_text()
     extra_modules = [
diff --git a/tests/config.py b/tests/config.py
index 6a00dea6..cfae0556 100644
--- a/tests/config.py
+++ b/tests/config.py
@@ -1,7 +1,7 @@
 from grimp.application.config import settings
 
 
-class override_settings:
+class override_settings:  # noqa: N801
     def __init__(self, **settings_to_override):
         self.settings_to_override = settings_to_override
 
diff --git a/tests/functional/test_build_and_use_graph.py b/tests/functional/test_build_and_use_graph.py
index ed151598..1d2f603a 100644
--- a/tests/functional/test_build_and_use_graph.py
+++ b/tests/functional/test_build_and_use_graph.py
@@ -1,6 +1,6 @@
-from grimp import build_graph
 import pytest
 
+from grimp import build_graph
 
 """
 For ease of reference, these are the imports of all the files:
diff --git a/tests/functional/test_build_and_use_graph_with_multiple_roots.py b/tests/functional/test_build_and_use_graph_with_multiple_roots.py
index 4c0efdcf..d8fda118 100644
--- a/tests/functional/test_build_and_use_graph_with_multiple_roots.py
+++ b/tests/functional/test_build_and_use_graph_with_multiple_roots.py
@@ -1,4 +1,5 @@
-import pytest  # type: ignore
+import pytest
+
 from grimp import build_graph
 
 """
diff --git a/tests/functional/test_build_graph_on_real_packages.py b/tests/functional/test_build_graph_on_real_packages.py
index b2da12af..63e5a4bf 100644
--- a/tests/functional/test_build_graph_on_real_packages.py
+++ b/tests/functional/test_build_graph_on_real_packages.py
@@ -1,4 +1,4 @@
-import pytest  # type: ignore
+import pytest
 
 import grimp
 
diff --git a/tests/functional/test_caching.py b/tests/functional/test_caching.py
index 1916abf9..f69ea8aa 100644
--- a/tests/functional/test_caching.py
+++ b/tests/functional/test_caching.py
@@ -2,7 +2,7 @@
 import tempfile
 from pathlib import Path
 
-import pytest  # type: ignore
+import pytest
 
 from grimp import build_graph
 
diff --git a/tests/functional/test_error_handling.py b/tests/functional/test_error_handling.py
index ab8f873b..955cc14f 100644
--- a/tests/functional/test_error_handling.py
+++ b/tests/functional/test_error_handling.py
@@ -1,6 +1,6 @@
 from pathlib import Path
 
-import pytest  # type: ignore
+import pytest
 
 from grimp import build_graph, exceptions
 
diff --git a/tests/functional/test_namespace_packages.py b/tests/functional/test_namespace_packages.py
index ac47d2cb..53c80424 100644
--- a/tests/functional/test_namespace_packages.py
+++ b/tests/functional/test_namespace_packages.py
@@ -1,4 +1,4 @@
-import pytest  # type: ignore
+import pytest
 
 from grimp import build_graph
 
diff --git a/tests/unit/adaptors/test_caching.py b/tests/unit/adaptors/test_caching.py
index 3f6576db..289d1ae2 100644
--- a/tests/unit/adaptors/test_caching.py
+++ b/tests/unit/adaptors/test_caching.py
@@ -1,13 +1,13 @@
 import json
 import logging
 
-import pytest  # type: ignore
+import pytest
 
+from grimp import _rustgrimp as rust  # type: ignore[attr-defined]
 from grimp.adaptors.caching import Cache, CacheFileNamer
 from grimp.application.ports.caching import CacheMiss
 from grimp.application.ports.modulefinder import FoundPackage, ModuleFile
 from grimp.domain.valueobjects import DirectImport, Module
-from grimp import _rustgrimp as rust  # type: ignore[attr-defined]
 
 
 class SimplisticFileNamer(CacheFileNamer):
diff --git a/tests/unit/adaptors/test_filesystem.py b/tests/unit/adaptors/test_filesystem.py
index 27dbbf17..3526e55c 100644
--- a/tests/unit/adaptors/test_filesystem.py
+++ b/tests/unit/adaptors/test_filesystem.py
@@ -1,9 +1,13 @@
-from typing import TypeAlias
+from __future__ import annotations
+
 from copy import copy
-import pytest  # type: ignore
+from typing import TypeAlias
+
+import pytest
+
+from grimp import _rustgrimp as rust  # type: ignore[attr-defined]
 from grimp.application.ports.filesystem import BasicFileSystem
 from tests.adaptors.filesystem import FakeFileSystem
-from grimp import _rustgrimp as rust  # type: ignore[attr-defined]
 
 
 class _Base:
diff --git a/tests/unit/adaptors/test_modulefinder.py b/tests/unit/adaptors/test_modulefinder.py
index 8cf2e3fc..ad5a84a6 100644
--- a/tests/unit/adaptors/test_modulefinder.py
+++ b/tests/unit/adaptors/test_modulefinder.py
@@ -1,8 +1,9 @@
+import pytest
+
 from grimp.adaptors.modulefinder import ModuleFinder
 from grimp.application.ports.modulefinder import FoundPackage, ModuleFile
 from grimp.domain.valueobjects import Module
 from tests.adaptors.filesystem import DEFAULT_MTIME, FakeFileSystem
-import pytest
 
 
 def test_happy_path():
@@ -131,8 +132,6 @@ def test_namespaced_packages(package_name: str, package_directory: str, expected
                     non_python_directory/
                         six/
                             README.txt
-                    
-                    
         """
     )
 
@@ -218,14 +217,14 @@ def test_ignores_invalid_identifier_directories():
 
     module_files = {
         ModuleFile(module=Module(name), mtime=DEFAULT_MTIME)
-        for name in {
+        for name in (
             "namespacepackage.foo.valid_underscore_name",
             "namespacepackage.foo.valid_underscore_name.mod",
             "namespacepackage.foo.valid_non_àscii",
             "namespacepackage.foo.valid_non_àscii.mod",
             "namespacepackage.bar",
             "namespacepackage.bar.mod",
-        }
+        )
     }
     assert result == FoundPackage(
         name="namespacepackage",
diff --git a/tests/unit/adaptors/test_packagefinder.py b/tests/unit/adaptors/test_packagefinder.py
index f7f2de62..2f687a29 100644
--- a/tests/unit/adaptors/test_packagefinder.py
+++ b/tests/unit/adaptors/test_packagefinder.py
@@ -1,10 +1,10 @@
 from pathlib import Path
 
-import pytest  # type: ignore
+import pytest
 
 from grimp import exceptions
-from grimp.adaptors.packagefinder import ImportLibPackageFinder
 from grimp.adaptors.filesystem import FileSystem
+from grimp.adaptors.packagefinder import ImportLibPackageFinder
 from tests.adaptors.filesystem import FakeFileSystem
 
 assets = (Path(__file__).parent.parent.parent / "assets").resolve()
diff --git a/tests/unit/application/graph/test_chains.py b/tests/unit/application/graph/test_chains.py
index 3fa3039e..4f960c1e 100644
--- a/tests/unit/application/graph/test_chains.py
+++ b/tests/unit/application/graph/test_chains.py
@@ -1,5 +1,6 @@
 import re
-import pytest  # type: ignore
+
+import pytest
 
 from grimp.application.graph import ImportGraph
 
diff --git a/tests/unit/application/graph/test_cycle_breakers.py b/tests/unit/application/graph/test_cycle_breakers.py
index 7e78881d..a829a6a7 100644
--- a/tests/unit/application/graph/test_cycle_breakers.py
+++ b/tests/unit/application/graph/test_cycle_breakers.py
@@ -1,5 +1,6 @@
-from grimp.application.graph import ImportGraph
 import pytest
+
+from grimp.application.graph import ImportGraph
 from grimp.exceptions import ModuleNotPresent
 
 
diff --git a/tests/unit/application/graph/test_direct_imports.py b/tests/unit/application/graph/test_direct_imports.py
index 871064a2..c70112ac 100644
--- a/tests/unit/application/graph/test_direct_imports.py
+++ b/tests/unit/application/graph/test_direct_imports.py
@@ -1,7 +1,8 @@
-import pytest  # type: ignore
+import re
+
+import pytest
 
 from grimp.application.graph import ImportGraph
-import re
 from grimp.exceptions import InvalidImportExpression
 
 
diff --git a/tests/unit/application/graph/test_hierarchy.py b/tests/unit/application/graph/test_hierarchy.py
index ce373dab..fa3550c1 100644
--- a/tests/unit/application/graph/test_hierarchy.py
+++ b/tests/unit/application/graph/test_hierarchy.py
@@ -1,8 +1,9 @@
 import re
-import pytest  # type: ignore
+
+import pytest
 
 from grimp.application.graph import ImportGraph
-from grimp.exceptions import ModuleNotPresent, InvalidModuleExpression
+from grimp.exceptions import InvalidModuleExpression, ModuleNotPresent
 
 
 @pytest.mark.parametrize(
diff --git a/tests/unit/application/graph/test_layers.py b/tests/unit/application/graph/test_layers.py
index c549d052..91da4f75 100644
--- a/tests/unit/application/graph/test_layers.py
+++ b/tests/unit/application/graph/test_layers.py
@@ -5,12 +5,12 @@
 import re
 from collections.abc import Iterable
 
-import pytest  # type: ignore
+import pytest
 
 from grimp import PackageDependency, Route
 from grimp.application.graph import ImportGraph
-from grimp.exceptions import NoSuchContainer
 from grimp.domain.valueobjects import Layer
+from grimp.exceptions import NoSuchContainer
 
 
 class TestSingleOrNoContainer:
diff --git a/tests/unit/application/graph/test_manipulation.py b/tests/unit/application/graph/test_manipulation.py
index 8824647c..d4854855 100644
--- a/tests/unit/application/graph/test_manipulation.py
+++ b/tests/unit/application/graph/test_manipulation.py
@@ -1,5 +1,6 @@
 import re
-import pytest  # type: ignore
+
+import pytest
 
 from grimp.application.graph import ImportGraph
 from grimp.exceptions import ModuleNotPresent
diff --git a/tests/unit/application/graph/test_misc.py b/tests/unit/application/graph/test_misc.py
index b0a4fa3a..c3668fa8 100644
--- a/tests/unit/application/graph/test_misc.py
+++ b/tests/unit/application/graph/test_misc.py
@@ -1,4 +1,4 @@
-import pytest  # type: ignore
+import pytest
 
 from grimp.application.graph import ImportGraph
 from grimp.exceptions import ModuleNotPresent
diff --git a/tests/unit/application/test_scanning.py b/tests/unit/application/test_scanning.py
index c0c1447a..28289220 100644
--- a/tests/unit/application/test_scanning.py
+++ b/tests/unit/application/test_scanning.py
@@ -1,11 +1,14 @@
-import pytest  # type: ignore
+from __future__ import annotations
 
-from grimp.application.ports.modulefinder import FoundPackage, ModuleFile
+from collections.abc import Set
+
+import pytest
+
+from grimp import _rustgrimp as rust  # type: ignore[attr-defined]
 from grimp.application import scanning
+from grimp.application.ports.modulefinder import FoundPackage, ModuleFile
 from grimp.domain.valueobjects import DirectImport, Module
 from tests.config import override_settings
-from grimp import _rustgrimp as rust  # type: ignore[attr-defined]
-from collections.abc import Set
 
 
 @pytest.mark.parametrize(
diff --git a/tests/unit/application/test_usecases.py b/tests/unit/application/test_usecases.py
index e7f2ae26..7c3da83e 100644
--- a/tests/unit/application/test_usecases.py
+++ b/tests/unit/application/test_usecases.py
@@ -1,6 +1,9 @@
+from __future__ import annotations
+
 import re
 from unittest.mock import sentinel
-import pytest  # type: ignore
+
+import pytest
 
 from grimp.application import usecases
 from grimp.application.ports.caching import Cache
diff --git a/tests/unit/conftest.py b/tests/unit/conftest.py
index d00899fd..dcd47608 100644
--- a/tests/unit/conftest.py
+++ b/tests/unit/conftest.py
@@ -1,7 +1,7 @@
-import pytest  # type: ignore
+import pytest
 
-from grimp.application.graph import ImportGraph
 from grimp.adaptors.modulefinder import ModuleFinder
+from grimp.application.graph import ImportGraph
 from tests.config import override_settings
 
 
diff --git a/tests/unit/domain/test_valueobjects.py b/tests/unit/domain/test_valueobjects.py
index cc883397..c6a07cd4 100644
--- a/tests/unit/domain/test_valueobjects.py
+++ b/tests/unit/domain/test_valueobjects.py
@@ -1,6 +1,6 @@
-import pytest  # type: ignore
+import pytest
 
-from grimp.domain.valueobjects import DirectImport, Module, Layer
+from grimp.domain.valueobjects import DirectImport, Layer, Module
 
 
 class TestModule: