diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 381303b5..47ed7557 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -9,7 +9,7 @@ jobs:
     timeout-minutes: 30
     strategy:
       matrix:
-        python-version: ['3.9','3.10','3.11','3.12']
+        python-version: ["3.10","3.11","3.12"]
 
     steps:
       - uses: actions/checkout@v4
@@ -27,9 +27,7 @@ jobs:
         env:
           # show timings of tests
           PYTEST_ADDOPTS: "--durations=0"
-        run: |
-          unset CI
-          uv run pytest --run-extra-mlips --cov janus_core --cov-append .
+        run: uv run pytest --run-extra-mlips --cov janus_core --cov-append .
 
       - name: Report coverage to Coveralls
         uses: coverallsapp/github-action@v2
diff --git a/.github/workflows/mac.yml b/.github/workflows/mac.yml
index f296f151..3e754e8c 100644
--- a/.github/workflows/mac.yml
+++ b/.github/workflows/mac.yml
@@ -10,7 +10,7 @@ jobs:
     timeout-minutes: 30
     strategy:
       matrix:
-        python-version: ['3.9','3.10','3.11','3.12']
+        python-version: ["3.10","3.11","3.12"]
 
     steps:
       - uses: actions/checkout@v4
diff --git a/README.md b/README.md
index 1cca1073..2f29d2cf 100644
--- a/README.md
+++ b/README.md
@@ -18,7 +18,7 @@ Tools for machine learnt interatomic potentials
 
 `janus-core` dependencies currently include:
 
-- Python >= 3.9
+- Python >= 3.10
 - ASE >= 3.23
 - mace-torch = 0.3.8
 - chgnet = 0.3.8 (optional)
diff --git a/docs/source/getting_started/getting_started.rst b/docs/source/getting_started/getting_started.rst
index 564e29e5..5efc7ca0 100644
--- a/docs/source/getting_started/getting_started.rst
+++ b/docs/source/getting_started/getting_started.rst
@@ -7,7 +7,7 @@ Dependencies
 
 ``janus-core`` dependencies currently include:
 
-- Python >= 3.9
+- Python >= 3.10
 - ASE >= 3.23
 - mace-torch = 0.3.8
 - chgnet = 0.3.8 (optional)
diff --git a/janus_core/calculations/eos.py b/janus_core/calculations/eos.py
index c2423e00..cb80b152 100644
--- a/janus_core/calculations/eos.py
+++ b/janus_core/calculations/eos.py
@@ -322,7 +322,9 @@ def run(self) -> EoSResults:
         if self.write_results:
             with open(f"{self.file_prefix}-eos-raw.dat", "w", encoding="utf8") as out:
                 print("#Lattice Scalar | Energy [eV] | Volume [Å^3] ", file=out)
-                for eos_data in zip(self.lattice_scalars, self.energies, self.volumes):
+                for eos_data in zip(
+                    self.lattice_scalars, self.energies, self.volumes, strict=True
+                ):
                     print(*eos_data, file=out)
 
         eos = EquationOfState(self.volumes, self.energies, self.eos_type)
diff --git a/janus_core/calculations/geom_opt.py b/janus_core/calculations/geom_opt.py
index 46c4f2ba..e3714e7c 100644
--- a/janus_core/calculations/geom_opt.py
+++ b/janus_core/calculations/geom_opt.py
@@ -2,7 +2,8 @@
 
 from __future__ import annotations
 
-from typing import Any, Callable
+from collections.abc import Callable
+from typing import Any
 import warnings
 
 from ase import Atoms, filters, units
diff --git a/janus_core/cli/descriptors.py b/janus_core/cli/descriptors.py
index eccedc36..a7f9defd 100644
--- a/janus_core/cli/descriptors.py
+++ b/janus_core/cli/descriptors.py
@@ -1,12 +1,9 @@
-# ruff: noqa: I002, FA100
 """Set up MLIP descriptors commandline interface."""
 
-# Issues with future annotations and typer
-# c.f. https://github.com/maxb2/typer-config/issues/295
-# from __future__ import annotations
+from __future__ import annotations
 
 from pathlib import Path
-from typing import Annotated, Optional
+from typing import Annotated
 
 from typer import Context, Option, Typer
 from typer_config import use_config
@@ -49,7 +46,7 @@ def descriptors(
     device: Device = "cpu",
     model_path: ModelPath = None,
     out: Annotated[
-        Optional[Path],
+        Path | None,
         Option(
             help=(
                 "Path to save structure with calculated descriptors. Default is "
diff --git a/janus_core/cli/eos.py b/janus_core/cli/eos.py
index 047c7398..96841243 100644
--- a/janus_core/cli/eos.py
+++ b/janus_core/cli/eos.py
@@ -1,12 +1,9 @@
-# ruff: noqa: I002, FA100
 """Set up eos commandline interface."""
 
-# Issues with future annotations and typer
-# c.f. https://github.com/maxb2/typer-config/issues/295
-# from __future__ import annotations
+from __future__ import annotations
 
 from pathlib import Path
-from typing import Annotated, Optional, get_args
+from typing import Annotated, get_args
 
 from typer import Context, Option, Typer
 from typer_config import use_config
@@ -66,7 +63,7 @@ def eos(
     read_kwargs: ReadKwargsLast = None,
     calc_kwargs: CalcKwargs = None,
     file_prefix: Annotated[
-        Optional[Path],
+        Path | None,
         Option(
             help=(
                 """
diff --git a/janus_core/cli/geomopt.py b/janus_core/cli/geomopt.py
index 5a504b4f..5a2a6aee 100644
--- a/janus_core/cli/geomopt.py
+++ b/janus_core/cli/geomopt.py
@@ -1,12 +1,9 @@
-# ruff: noqa: I002, FA100
 """Set up geomopt commandline interface."""
 
-# Issues with future annotations and typer
-# c.f. https://github.com/maxb2/typer-config/issues/295
-# from __future__ import annotations
+from __future__ import annotations
 
 from pathlib import Path
-from typing import Annotated, Any, Optional
+from typing import Annotated, Any
 
 from typer import Context, Option, Typer
 from typer_config import use_config
@@ -30,7 +27,7 @@
 
 def _set_minimize_kwargs(
     minimize_kwargs: dict[str, Any],
-    traj: Optional[str],
+    traj: str | None,
     opt_cell_lengths: bool,
     pressure: float,
 ) -> None:
@@ -91,7 +88,7 @@ def geomopt(
     ctx: Context,
     struct: StructPath,
     optimizer: Annotated[
-        Optional[str],
+        str | None,
         Option(help="Name of ASE optimizer function to use."),
     ] = "LBFGS",
     fmax: Annotated[
@@ -112,7 +109,7 @@ def geomopt(
         ),
     ] = False,
     filter_func: Annotated[
-        Optional[str],
+        str | None,
         Option(
             help=(
                 "Name of ASE filter/constraint function to use. If using "
@@ -134,7 +131,7 @@ def geomopt(
         ),
     ] = 0.001,
     out: Annotated[
-        Optional[Path],
+        Path | None,
         Option(
             help=(
                 "Path to save optimized structure. Default is inferred from name "
diff --git a/janus_core/cli/janus.py b/janus_core/cli/janus.py
index 1a4f3732..66a61943 100644
--- a/janus_core/cli/janus.py
+++ b/janus_core/cli/janus.py
@@ -1,9 +1,6 @@
-# ruff: noqa: I002, FA100
 """Set up commandline interface."""
 
-# Issues with future annotations and typer
-# c.f. https://github.com/maxb2/typer-config/issues/295
-# from __future__ import annotations
+from __future__ import annotations
 
 from typing import Annotated
 
@@ -39,7 +36,7 @@ def print_version(
     version: Annotated[
         bool, Option("--version", help="Print janus version and exit.")
     ] = None,
-) -> False:
+) -> None:
     """
     Print current janus-core version and exit.
 
diff --git a/janus_core/cli/md.py b/janus_core/cli/md.py
index 515d86fd..eb435ace 100644
--- a/janus_core/cli/md.py
+++ b/janus_core/cli/md.py
@@ -1,12 +1,9 @@
-# ruff: noqa: I002, FA100
 """Set up md commandline interface."""
 
-# Issues with future annotations and typer
-# c.f. https://github.com/maxb2/typer-config/issues/295
-# from __future__ import annotations
+from __future__ import annotations
 
 from pathlib import Path
-from typing import Annotated, Optional, get_args
+from typing import Annotated, get_args
 
 from typer import Context, Option, Typer
 from typer_config import use_config
@@ -101,7 +98,7 @@ def md(
         int, Option(help="Frequency to rescale velocities during equilibration.")
     ] = 10,
     file_prefix: Annotated[
-        Optional[Path],
+        Path | None,
         Option(
             help=(
                 """
@@ -116,7 +113,7 @@ def md(
         bool, Option(help="Whether to infer restart file if restarting dynamics.")
     ] = True,
     restart_stem: Annotated[
-        Optional[Path],
+        Path | None,
         Option(help="Stem for restart file name. Default inferred from `file_prefix`."),
     ] = None,
     restart_every: Annotated[
@@ -129,7 +126,7 @@ def md(
         int, Option(help="Restart files to keep if rotating.")
     ] = 4,
     final_file: Annotated[
-        Optional[Path],
+        Path | None,
         Option(
             help=(
                 """
@@ -140,7 +137,7 @@ def md(
         ),
     ] = None,
     stats_file: Annotated[
-        Optional[Path],
+        Path | None,
         Option(
             help=(
                 """
@@ -152,7 +149,7 @@ def md(
     ] = None,
     stats_every: Annotated[int, Option(help="Frequency to output statistics.")] = 100,
     traj_file: Annotated[
-        Optional[Path],
+        Path | None,
         Option(help="File to save trajectory. Default inferred from `file_prefix`."),
     ] = None,
     traj_append: Annotated[bool, Option(help="Whether to append trajectory.")] = False,
@@ -161,23 +158,23 @@ def md(
         int, Option(help="Frequency of steps to save trajectory.")
     ] = 100,
     temp_start: Annotated[
-        Optional[float],
+        float | None,
         Option(help="Temperature to start heating, in K."),
     ] = None,
     temp_end: Annotated[
-        Optional[float],
+        float | None,
         Option(help="Maximum temperature for heating, in K."),
     ] = None,
     temp_step: Annotated[
-        Optional[float], Option(help="Size of temperature steps when heating, in K.")
+        float | None, Option(help="Size of temperature steps when heating, in K.")
     ] = None,
     temp_time: Annotated[
-        Optional[float], Option(help="Time between heating steps, in fs.")
+        float | None, Option(help="Time between heating steps, in fs.")
     ] = None,
     write_kwargs: WriteKwargs = None,
     post_process_kwargs: PostProcessKwargs = None,
     seed: Annotated[
-        Optional[int],
+        int | None,
         Option(help="Random seed for numpy.random and random functions."),
     ] = None,
     log: LogPath = None,
diff --git a/janus_core/cli/phonons.py b/janus_core/cli/phonons.py
index 85724fb8..02387395 100644
--- a/janus_core/cli/phonons.py
+++ b/janus_core/cli/phonons.py
@@ -1,12 +1,9 @@
-# ruff: noqa: I002, FA100
 """Set up phonons commandline interface."""
 
-# Issues with future annotations and typer
-# c.f. https://github.com/maxb2/typer-config/issues/295
-# from __future__ import annotations
+from __future__ import annotations
 
 from pathlib import Path
-from typing import Annotated, Optional
+from typing import Annotated
 
 from typer import Context, Option, Typer
 from typer_config import use_config
@@ -67,7 +64,7 @@ def phonons(
         ),
     ] = 51,
     qpoint_file: Annotated[
-        Optional[Path],
+        Path | None,
         Option(
             help=(
                 "Path to yaml file with info to generate a path of q-points for band "
@@ -125,7 +122,7 @@ def phonons(
     read_kwargs: ReadKwargsLast = None,
     calc_kwargs: CalcKwargs = None,
     file_prefix: Annotated[
-        Optional[Path],
+        Path | None,
         Option(
             help=(
                 """
diff --git a/janus_core/cli/preprocess.py b/janus_core/cli/preprocess.py
index be1b4ca8..614ffe1f 100644
--- a/janus_core/cli/preprocess.py
+++ b/janus_core/cli/preprocess.py
@@ -1,9 +1,6 @@
-# noqa: I002, FA102
 """Set up MLIP preprocessing commandline interface."""
 
-# Issues with future annotations and typer
-# c.f. https://github.com/maxb2/typer-config/issues/295
-# from __future__ import annotations
+from __future__ import annotations
 
 from pathlib import Path
 from typing import Annotated
diff --git a/janus_core/cli/singlepoint.py b/janus_core/cli/singlepoint.py
index 059edd59..0635ffa6 100644
--- a/janus_core/cli/singlepoint.py
+++ b/janus_core/cli/singlepoint.py
@@ -1,12 +1,9 @@
-# ruff: noqa: I002, FA100
 """Set up singlepoint commandline interface."""
 
-# Issues with future annotations and typer
-# c.f. https://github.com/maxb2/typer-config/issues/295
-# from __future__ import annotations
+from __future__ import annotations
 
 from pathlib import Path
-from typing import Annotated, Optional
+from typing import Annotated
 
 from typer import Context, Option, Typer
 from typer_config import use_config
@@ -37,7 +34,7 @@ def singlepoint(
     device: Device = "cpu",
     model_path: ModelPath = None,
     properties: Annotated[
-        Optional[list[str]],
+        list[str] | None,
         Option(
             help=(
                 "Properties to calculate. If not specified, 'energy', 'forces' "
@@ -46,7 +43,7 @@ def singlepoint(
         ),
     ] = None,
     out: Annotated[
-        Optional[Path],
+        Path | None,
         Option(
             help=(
                 "Path to save structure with calculated results. Default is inferred "
diff --git a/janus_core/cli/train.py b/janus_core/cli/train.py
index 197ca272..de687f93 100644
--- a/janus_core/cli/train.py
+++ b/janus_core/cli/train.py
@@ -1,9 +1,6 @@
-# noqa: I002, FA102
 """Set up MLIP training commandline interface."""
 
-# Issues with future annotations and typer
-# c.f. https://github.com/maxb2/typer-config/issues/295
-# from __future__ import annotations
+from __future__ import annotations
 
 from pathlib import Path
 from typing import Annotated
diff --git a/janus_core/cli/types.py b/janus_core/cli/types.py
index b37e8a70..c8e73842 100644
--- a/janus_core/cli/types.py
+++ b/janus_core/cli/types.py
@@ -4,7 +4,7 @@
 
 import ast
 from pathlib import Path
-from typing import TYPE_CHECKING, Annotated, Optional
+from typing import TYPE_CHECKING, Annotated
 
 from typer import Option
 
@@ -67,13 +67,13 @@ def __str__(self) -> str:
 StructPath = Annotated[Path, Option(help="Path of structure to simulate.")]
 
 Architecture = Annotated[
-    Optional[str], Option(help="MLIP architecture to use for calculations.")
+    str | None, Option(help="MLIP architecture to use for calculations.")
 ]
-Device = Annotated[Optional[str], Option(help="Device to run calculations on.")]
-ModelPath = Annotated[Optional[str], Option(help="Path to MLIP model.")]
+Device = Annotated[str | None, Option(help="Device to run calculations on.")]
+ModelPath = Annotated[str | None, Option(help="Path to MLIP model.")]
 
 ReadKwargsAll = Annotated[
-    Optional[TyperDict],
+    TyperDict | None,
     Option(
         parser=parse_dict_class,
         help=(
@@ -88,7 +88,7 @@ def __str__(self) -> str:
 ]
 
 ReadKwargsLast = Annotated[
-    Optional[TyperDict],
+    TyperDict | None,
     Option(
         parser=parse_dict_class,
         help=(
@@ -103,7 +103,7 @@ def __str__(self) -> str:
 ]
 
 CalcKwargs = Annotated[
-    Optional[TyperDict],
+    TyperDict | None,
     Option(
         parser=parse_dict_class,
         help=(
@@ -118,7 +118,7 @@ def __str__(self) -> str:
 ]
 
 WriteKwargs = Annotated[
-    Optional[TyperDict],
+    TyperDict | None,
     Option(
         parser=parse_dict_class,
         help=(
@@ -132,7 +132,7 @@ def __str__(self) -> str:
 ]
 
 OptKwargs = Annotated[
-    Optional[TyperDict],
+    TyperDict | None,
     Option(
         parser=parse_dict_class,
         help=(
@@ -146,7 +146,7 @@ def __str__(self) -> str:
 ]
 
 MinimizeKwargs = Annotated[
-    Optional[TyperDict],
+    TyperDict | None,
     Option(
         parser=parse_dict_class,
         help=(
@@ -160,7 +160,7 @@ def __str__(self) -> str:
 ]
 
 DoSKwargs = Annotated[
-    Optional[TyperDict],
+    TyperDict | None,
     Option(
         parser=parse_dict_class,
         help=(
@@ -174,7 +174,7 @@ def __str__(self) -> str:
 ]
 
 PDoSKwargs = Annotated[
-    Optional[TyperDict],
+    TyperDict | None,
     Option(
         parser=parse_dict_class,
         help=(
@@ -188,7 +188,7 @@ def __str__(self) -> str:
 ]
 
 EnsembleKwargs = Annotated[
-    Optional[TyperDict],
+    TyperDict | None,
     Option(
         parser=parse_dict_class,
         help=(
@@ -202,7 +202,7 @@ def __str__(self) -> str:
 ]
 
 DisplacementKwargs = Annotated[
-    Optional[TyperDict],
+    TyperDict | None,
     Option(
         parser=parse_dict_class,
         help=(
@@ -216,7 +216,7 @@ def __str__(self) -> str:
 ]
 
 PostProcessKwargs = Annotated[
-    Optional[TyperDict],
+    TyperDict | None,
     Option(
         parser=parse_dict_class,
         help=(
@@ -230,7 +230,7 @@ def __str__(self) -> str:
 ]
 
 LogPath = Annotated[
-    Optional[Path],
+    Path | None,
     Option(
         help=(
             "Path to save logs to. Default is inferred from the name of the structure "
@@ -240,7 +240,7 @@ def __str__(self) -> str:
 ]
 
 Summary = Annotated[
-    Optional[Path],
+    Path | None,
     Option(
         help=(
             "Path to save summary of inputs, start/end time, and carbon emissions. "
diff --git a/janus_core/helpers/janus_types.py b/janus_core/helpers/janus_types.py
index 4533f4f5..f31a4b8b 100644
--- a/janus_core/helpers/janus_types.py
+++ b/janus_core/helpers/janus_types.py
@@ -6,7 +6,7 @@
 from enum import Enum
 import logging
 from pathlib import Path, PurePath
-from typing import IO, TYPE_CHECKING, Literal, Optional, TypedDict, TypeVar, Union
+from typing import IO, TYPE_CHECKING, Literal, TypedDict, TypeVar
 
 from ase import Atoms
 from ase.eos import EquationOfState
@@ -19,11 +19,11 @@
 # General
 
 T = TypeVar("T")
-MaybeList = Union[T, list[T]]
-MaybeSequence = Union[T, Sequence[T]]
-PathLike = Union[str, Path]
-StartStopStep = tuple[Optional[int], Optional[int], int]
-SliceLike = Union[slice, range, int, StartStopStep]
+MaybeList = T | list[T]
+MaybeSequence = T | Sequence[T]
+PathLike = str | Path
+StartStopStep = tuple[int | None, int | None, int]
+SliceLike = slice | range | int | StartStopStep
 
 # ASE Arg types
 
diff --git a/janus_core/helpers/mlip_calculators.py b/janus_core/helpers/mlip_calculators.py
index 537dc027..6fd2401a 100644
--- a/janus_core/helpers/mlip_calculators.py
+++ b/janus_core/helpers/mlip_calculators.py
@@ -64,7 +64,7 @@ def _set_model_path(
         model_path = kwargs.pop(present.pop())
 
     # Convert to path if file/directory exists
-    if isinstance(model_path, (Path, str)) and Path(model_path).expanduser().exists():
+    if isinstance(model_path, Path | str) and Path(model_path).expanduser().exists():
         return Path(model_path).expanduser()
     return model_path
 
diff --git a/janus_core/helpers/stats.py b/janus_core/helpers/stats.py
index f0f5fbb4..7ee1cdcf 100644
--- a/janus_core/helpers/stats.py
+++ b/janus_core/helpers/stats.py
@@ -205,7 +205,7 @@ def data_tags(self) -> Iterator[tuple[str, str]]:
         Iterator[tuple[str, str]]
             Zipped labels and units.
         """
-        return zip(self.labels, self.units)
+        return zip(self.labels, self.units, strict=True)
 
     def read(self) -> None:
         """Read MD stats and store them in `data`."""
diff --git a/janus_core/helpers/struct_io.py b/janus_core/helpers/struct_io.py
index 5d6144fd..2d3c0c16 100644
--- a/janus_core/helpers/struct_io.py
+++ b/janus_core/helpers/struct_io.py
@@ -183,7 +183,7 @@ def input_structs(
             struct = struct[0]
 
     # Check struct is valid type
-    if not isinstance(struct, (Atoms, Sequence)) or isinstance(struct, str):
+    if not isinstance(struct, Atoms | Sequence) or isinstance(struct, str):
         raise ValueError("`struct` must be an ASE Atoms object or sequence of Atoms")
 
     # Check struct is valid length
diff --git a/janus_core/helpers/utils.py b/janus_core/helpers/utils.py
index b1976c32..0c71f4b9 100644
--- a/janus_core/helpers/utils.py
+++ b/janus_core/helpers/utils.py
@@ -339,7 +339,7 @@ def _dump_ascii(
     if header:
         print(f"# {' | '.join(header)}", file=file)
 
-    for cols in zip(*columns.values()):
+    for cols in zip(*columns.values(), strict=True):
         print(*map(format, cols, formats), file=file)
 
 
@@ -371,7 +371,7 @@ def _dump_csv(
     if header:
         print(",".join(header), file=file)
 
-    for cols in zip(*columns.values()):
+    for cols in zip(*columns.values(), strict=True):
         print(",".join(map(format, cols, formats)), file=file)
 
 
@@ -453,7 +453,7 @@ def validate_slicelike(maybe_slicelike: SliceLike) -> None:
     ValueError
         If maybe_slicelike is not SliceLike.
     """
-    if isinstance(maybe_slicelike, (slice, range, int)):
+    if isinstance(maybe_slicelike, slice | range | int):
         return
     if isinstance(maybe_slicelike, tuple) and len(maybe_slicelike) == 3:
         start, stop, step = maybe_slicelike
@@ -487,7 +487,7 @@ def slicelike_to_startstopstep(index: SliceLike) -> StartStopStep:
             return (index, None, 1)
         return (index, index + 1, 1)
 
-    if isinstance(index, (slice, range)):
+    if isinstance(index, slice | range):
         return (index.start, index.stop, index.step)
 
     return index
diff --git a/janus_core/processing/correlator.py b/janus_core/processing/correlator.py
index 4328d20d..6461c4c8 100644
--- a/janus_core/processing/correlator.py
+++ b/janus_core/processing/correlator.py
@@ -326,7 +326,9 @@ def update(self, atoms: Atoms) -> None:
             Atoms object to observe values from.
         """
         # All pairs of data to be correlated.
-        value_pairs = zip(self._get_a(atoms).flatten(), self._get_b(atoms).flatten())
+        value_pairs = zip(
+            self._get_a(atoms).flatten(), self._get_b(atoms).flatten(), strict=True
+        )
         if self._correlators is None:
             # Initialise correlators automatically.
             self._correlators = [
@@ -335,7 +337,7 @@ def update(self, atoms: Atoms) -> None:
                 )
                 for _ in range(len(self._get_a(atoms).flatten()))
             ]
-        for corr, values in zip(self._correlators, value_pairs):
+        for corr, values in zip(self._correlators, value_pairs, strict=True):
             corr.update(*values)
 
     def get(self) -> tuple[Iterable[float], Iterable[float]]:
diff --git a/janus_core/processing/post_process.py b/janus_core/processing/post_process.py
index 2c9a66ff..3e46a92a 100644
--- a/janus_core/processing/post_process.py
+++ b/janus_core/processing/post_process.py
@@ -122,9 +122,9 @@ def compute_rdf(
                     f"to number of samples ({len(rdf)})"
                 )
 
-            for (dists, rdfs), out_path in zip(rdf.values(), filenames):
+            for (dists, rdfs), out_path in zip(rdf.values(), filenames, strict=True):
                 with open(out_path, "w", encoding="utf-8") as out_file:
-                    for dist, rdf_i in zip(dists, rdfs):
+                    for dist, rdf_i in zip(dists, rdfs, strict=True):
                         print(dist, rdf_i, file=out_file)
 
     else:
@@ -152,7 +152,7 @@ def compute_rdf(
                 filenames = filenames[0]
 
             with open(filenames, "w", encoding="utf-8") as out_file:
-                for dist, rdf_i in zip(*rdf):
+                for dist, rdf_i in zip(*rdf, strict=True):
                     print(dist, rdf_i, file=out_file)
 
     return rdf
@@ -287,9 +287,9 @@ def compute_vaf(
     )
 
     if filenames:
-        for vaf, filename in zip(vafs[1], filenames):
+        for vaf, filename in zip(vafs[1], filenames, strict=True):
             with open(filename, "w", encoding="utf-8") as out_file:
-                for lag, dat in zip(lags, vaf):
+                for lag, dat in zip(lags, vaf, strict=True):
                     print(lag, dat, file=out_file)
 
     return vafs
diff --git a/pyproject.toml b/pyproject.toml
index 38854ebf..c1e53f36 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -11,7 +11,7 @@ authors = [
     { name = "Jacob Wilkins" },
     { name = "Alin M. Elena" },
 ]
-requires-python = "<3.13,>=3.9"
+requires-python = ">=3.10"
 classifiers = [
     "Programming Language :: Python",
     "Intended Audience :: Science/Research",
@@ -34,7 +34,7 @@ dependencies = [
     "torch<=2.2,>=2.1",
     "torch-dftd==0.4.0",
     "typer<1.0.0,>=0.12.5",
-    "typer-config<2.0.0,>=1.4.0",
+    "typer-config<2.0.0,>=1.4.2",
 ]
 
 [project.optional-dependencies]
@@ -107,7 +107,7 @@ source=["janus_core"]
 
 [tool.ruff]
 exclude = ["conf.py"]
-target-version = "py39"
+target-version = "py310"
 
 [tool.ruff.lint]
 # Ignore complexity
diff --git a/tests/test_md_cli.py b/tests/test_md_cli.py
index 16c05bf9..970c84cc 100644
--- a/tests/test_md_cli.py
+++ b/tests/test_md_cli.py
@@ -257,7 +257,9 @@ def test_seed(tmp_path):
 
         final_stats_2 = lines[2].split()
 
-    for i, (stats_1, stats_2) in enumerate(zip(final_stats_1, final_stats_2)):
+    for i, (stats_1, stats_2) in enumerate(
+        zip(final_stats_1, final_stats_2, strict=True)
+    ):
         if i != 1:
             assert stats_1 == stats_2
 
diff --git a/tox.ini b/tox.ini
index 4057dbf3..925e8f5e 100644
--- a/tox.ini
+++ b/tox.ini
@@ -5,7 +5,7 @@ envlist = py311
 usedevelop=True
 uv_sync_flags=--python={env_python}
 
-[testenv:py{39,310,311,312}]
+[testenv:py{310,311,312}]
 runner = uv-venv-lock-runner
 extras = all
 with_dev = True