diff --git a/lethe/__init__.py b/lethe/__init__.py
index df9b3fb..884d33b 100644
--- a/lethe/__init__.py
+++ b/lethe/__init__.py
@@ -2,24 +2,13 @@
 Git snapshotting tool
 """
 from .lethe import (
-    snap as snap,
-    snap_ref as snap_ref,
-    snap_tree as snap_tree,
-    find_merge_base as find_merge_base,
-    deref_symref as deref_symref,
-    update_ref as update_ref,
-    commit_tree as commit_tree,
-    get_tree as get_tree,
-    get_commit as get_commit,
-    get_obj as get_obj,
-    shorten_hash as shorten_hash,
-    get_root as get_root,
-    get_latest_commit as get_latest_commit,
-    push_ref as push_ref,
-    fetch_ref as fetch_ref,
+    snap, snap_ref, snap_tree, find_merge_base, deref_symref,
+    update_ref, commit_tree, get_tree, get_commit, get_obj,
+    shorten_hash, get_root, get_latest_commit,
+    push_ref, fetch_ref,
     )
 
-from .endpoints import main as main
+from .endpoints import main
 
 __author__ = 'Jan Petykeiwicz'
 __version__ = '0.13'
diff --git a/lethe/lethe.py b/lethe/lethe.py
index d2d01d8..c6a7dbe 100755
--- a/lethe/lethe.py
+++ b/lethe/lethe.py
@@ -3,14 +3,15 @@
 Git snapshotting tool
 """
 
-from typing import Sequence
+from typing import Sequence, Union, Optional
 import subprocess
 import tempfile
 import datetime
+import argparse
 from itertools import chain
 
 
-def _run(command: str | Sequence[str], **kwargs) -> str:
+def _run(command: Union[str, Sequence[str]], **kwargs) -> str:
     """
     Wrapper for `subprocess.run()`:
 
@@ -33,7 +34,7 @@ def _run(command: str | Sequence[str], **kwargs) -> str:
     return result.stdout.decode().strip()
 
 
-def get_latest_commit(short: bool = True, cwd: str | None = None) -> str:
+def get_latest_commit(short: bool = True, cwd: Optional[str] = None) -> str:
     """
     Get the most recent commit's hash.
     This includes non-lethe commits.
@@ -42,14 +43,14 @@ def get_latest_commit(short: bool = True, cwd: str | None = None) -> str:
     return _run(f'git log --all -1 --format=%{fmt}', cwd=cwd)
 
 
-def shorten_hash(sha: str, cwd: str | None = None) -> str:
+def shorten_hash(sha: str, cwd: Optional[str] = None) -> str:
     """
     Get the short version of a hash
     """
     return _run(f'git rev-parse --short {sha}', cwd=cwd)
 
 
-def get_root(cwd: str | None = None) -> str:
+def get_root(cwd: Optional[str] = None) -> str:
     """
     Get the root directory of a git repository
     """
@@ -59,7 +60,7 @@ def get_root(cwd: str | None = None) -> str:
     return root
 
 
-def get_obj(ref: str, cwd: str | None = None) -> str:
+def get_obj(ref: str, cwd: Optional[str] = None) -> str:
     """
     Transform a ref into its corresponding hash using git-rev-parse
     """
@@ -67,26 +68,25 @@ def get_obj(ref: str, cwd: str | None = None) -> str:
     return sha
 
 
-def get_commit(ref: str, cwd: str | None = None) -> str:
+def get_commit(ref: str, cwd: Optional[str] = None) -> str:
     """
     Transform a ref to a commit into its corresponding hash using git-rev-parse
     """
     return get_obj(ref, cwd=cwd)
 
 
-def get_tree(ref: str, cwd: str | None = None) -> str:
+def get_tree(ref: str, cwd: Optional[str] = None) -> str:
     """
     Take a ref to a commit, and return the hash of the tree it points to
     """
     return get_obj(ref + ':', cwd=cwd)
 
 
-def commit_tree(
-        tree: str,
-        parents: Sequence[str],
-        message: str | None = None,
-        cwd: str | None = None,
-        ) -> str:
+def commit_tree(tree: str,
+                parents: Sequence[str],
+                message: Optional[str] = None,
+                cwd: Optional[str] = None,
+                ) -> str:
     """
     Create a commit pointing to the given tree, with the specified parent commits and message.
     Return the hash of the created commit.
@@ -99,14 +99,13 @@ def commit_tree(
     return commit
 
 
-def update_ref(
-        target_ref: str,
-        target_commit: str,
-        old_commit: str | None = None,
-        *,
-        message: str = 'new snapshot',
-        cwd: str | None = None,
-        ) -> str:
+def update_ref(target_ref: str,
+               target_commit: str,
+               old_commit: Optional[str] = None,
+               *,
+               message: str = 'new snapshot',
+               cwd: Optional[str] = None,
+               ) -> str:
     """
     Update `target_ref` to point to `target_commit`, optionally verifying that
         it points `old_commit` before the update.
@@ -119,13 +118,12 @@ def update_ref(
     return result_ref
 
 
-def push_ref(
-        remote: str = 'origin',
-        target_ref: str = 'refs/lethe/LATEST',
-        remote_ref: str | None = None,
-        *,
-        cwd: str | None = None,
-        ) -> str:
+def push_ref(remote: str = 'origin',
+             target_ref: str = 'refs/lethe/LATEST',
+             remote_ref: Optional[str] = None,
+             *,
+             cwd: Optional[str] = None,
+             ) -> str:
     """
     Push `target_ref` to `remote` as `remote_ref`.
     By default, `remote_ref` will be the same as `target_ref`.
@@ -144,13 +142,12 @@ def push_ref(
     return _run(['git', 'push', '--force', remote, target_ref + ':' + remote_ref], cwd=cwd)
 
 
-def fetch_ref(
-        remote: str = 'origin',
-        remote_ref: str = 'refs/lethe/LATEST',
-        target_ref: str | None = None,
-        *,
-        cwd: str | None = None,
-        ) -> str:
+def fetch_ref(remote: str = 'origin',
+              remote_ref: str = 'refs/lethe/LATEST',
+              target_ref: Optional[str] = None,
+              *,
+              cwd: Optional[str] = None,
+              ) -> str:
     """
     Fetch `remote_ref` from `remote` as `target_ref`.
     By default, `target_ref` will be the same as `remote_ref`.
@@ -169,22 +166,20 @@ def fetch_ref(
     return _run(['git', 'fetch', '--force', remote, remote_ref + ':' + target_ref], cwd=cwd)
 
 
-def deref_symref(
-        ref: str,
-        *,
-        cwd: str | None = None,
-        ) -> str:
+def deref_symref(ref: str,
+                 *,
+                 cwd: Optional[str] = None,
+                 ) -> str:
     """
     Dereference a symbolic ref
     """
     return _run(['git', 'symbolic-ref', '--quiet', ref], cwd=cwd)
 
 
-def find_merge_base(
-        commits: Sequence[str],
-        *,
-        cwd: str | None = None,
-        ) -> str:
+def find_merge_base(commits: Sequence[str],
+                    *,
+                    cwd: Optional[str] = None,
+                    ) -> str:
     """
     Find the "best common ancestor" commit.
 
@@ -205,7 +200,7 @@ def find_merge_base(
     return base
 
 
-def snap_tree(*, cwd: str | None = None) -> str:
+def snap_tree(*, cwd: Optional[str] = None) -> str:
     """
     Create a new tree, consisting of all non-ignored files in the repository.
     Return the hash of the tree.
@@ -219,13 +214,12 @@ def snap_tree(*, cwd: str | None = None) -> str:
     return tree
 
 
-def snap_ref(
-        parent_refs: Sequence[str],
-        target_refs: Sequence[str],
-        message: str | None = None,
-        *,
-        cwd: str | None = None,
-        ) -> str:
+def snap_ref(parent_refs: Sequence[str],
+             target_refs: Sequence[str],
+             message: Optional[str] = None,
+             *,
+             cwd: Optional[str] = None,
+             ) -> str:
     """
     `message` is used as the commit message.
     """
@@ -233,7 +227,7 @@ def snap_ref(
     parent_commits = [c for c in [get_commit(p, cwd=cwd) for p in parent_refs] if c]
     old_commits = [get_commit(t, cwd=cwd) for t in target_refs]
 
-    commit = commit_tree(new_tree, list(set(parent_commits)), message, cwd=cwd)
+    commit = commit_tree(new_tree, set(parent_commits), message, cwd=cwd)
 
     for target_ref, old_commit in zip(target_refs, old_commits):
         # update ref to point to commit, or create new ref
@@ -243,13 +237,12 @@ def snap_ref(
     return commit
 
 
-def snap(
-        parent_refs: Sequence[str] | None = None,
-        target_refs: Sequence[str] | None = None,
-        message: str | None = None,
-        *,
-        cwd: str | None = None,
-        ) -> str:
+def snap(parent_refs: Optional[Sequence[str]] = None,
+         target_refs: Optional[Sequence[str]] = None,
+         message: Optional[str] = None,
+         *,
+         cwd: Optional[str] = None,
+         ) -> str:
     """
     Create a new commit, containing all non-ignored files.
 
@@ -298,7 +291,7 @@ def snap(
             old_base_commit = get_commit(target_base, cwd=cwd)
             if old_base_commit:
                 print(f'Migrating {target_base} to new naming scheme ({target_base}/LEGACY)...')
-                print('You may also want to delete refs/lethe/HEAD with `git update-ref -d refs/lethe/HEAD`')
+                print(f'You may also want to delete refs/lethe/HEAD with `git update-ref -d refs/lethe/HEAD`')
                 _run('git update-ref -d ' + target_base)
                 update_ref(target_base + '/LEGACY', old_base_commit,
                            message='last commit using old refs/lethe/branchname approach')
diff --git a/pyproject.toml b/pyproject.toml
index 8c0db70..4264cad 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -46,37 +46,3 @@ path = "lethe/__init__.py"
 lethe = "lethe.endpoints:main"
 lethe-push = "lethe.endpoints:push"
 lethe-fetch = "lethe.endpoints:fetch"
-
-
-[tool.ruff]
-exclude = [
-    ".git",
-    "dist",
-    ]
-line-length = 145
-indent-width = 4
-lint.dummy-variable-rgx = "^(_+|(_+[a-zA-Z0-9_]*[a-zA-Z0-9]+?))$"
-lint.select = [
-    "NPY", "E", "F", "W", "B", "ANN", "UP", "SLOT", "SIM", "LOG",
-    "C4", "ISC", "PIE", "PT", "RET", "TCH", "PTH", "INT",
-    "ARG", "PL", "R", "TRY",
-    "G010", "G101", "G201", "G202",
-    "Q002", "Q003", "Q004",
-    ]
-lint.ignore = [
-    #"ANN001",   # No annotation
-    "ANN002",   # *args
-    "ANN003",   # **kwargs
-    "ANN401",   # Any
-    "ANN101",   # self: Self
-    "SIM108",   # single-line if / else assignment
-    "RET504",   # x=y+z; return x
-    "PIE790",   # unnecessary pass
-    "ISC003",   # non-implicit string concatenation
-    "C408",     # dict(x=y) instead of {'x': y}
-    "PLR09",    # Too many xxx
-    "PLR2004",  # magic number
-    "PLC0414",  # import x as x
-    "TRY003",   # Long exception message
-    ]
-