diff --git a/2024/src/aoc/__main__.py b/2024/src/aoc/__main__.py
index 9534731..ce5d38a 100644
--- a/2024/src/aoc/__main__.py
+++ b/2024/src/aoc/__main__.py
@@ -22,11 +22,11 @@ from aoc import days
 @click.argument("day", required=True)
 def main(day: int, timing: bool, data: IO[str]) -> None:
     runner_class = days.get_runner(day)
-    data = data.read()
+    contents = data.read()
 
     start = time.perf_counter_ns()
 
-    part1, part2 = runner_class.run_both(data)
+    part1, part2 = runner_class.run_both(contents)
 
     if timing:
         elapsed = time.perf_counter_ns() - start
diff --git a/2024/src/aoc/days/day1.py b/2024/src/aoc/days/day1.py
index 5fcb923..3fe7f98 100644
--- a/2024/src/aoc/days/day1.py
+++ b/2024/src/aoc/days/day1.py
@@ -10,8 +10,7 @@ from . import CombinedRunner
 class DayRunner(CombinedRunner):
     @classmethod
     def run_both(cls, data: str) -> tuple[Any, Any]:
-        data = StringIO(data)
-        nums = numpy.loadtxt(data, dtype=numpy.int32)
+        nums = numpy.loadtxt(StringIO(data), dtype=numpy.int32)
 
         left = nums[..., 0]
         right = nums[..., 1]
@@ -21,7 +20,7 @@ class DayRunner(CombinedRunner):
 
         diff = numpy.abs(left - right).sum()
 
-        counts = defaultdict(int)
+        counts: defaultdict[int, int] = defaultdict(int)
         for val in right:
             counts[val] += 1
 
diff --git a/2024/tests/test_day1.py b/2024/tests/test_day1.py
index b6650bb..6ef1fde 100644
--- a/2024/tests/test_day1.py
+++ b/2024/tests/test_day1.py
@@ -2,13 +2,16 @@ import os
 
 from aoc.days.day1 import DayRunner
 
+
 def get_data() -> str:
     sample = os.path.dirname(__file__) + "/samples/01.txt"
     with open(sample, mode="rt", encoding="utf-8") as f:
         return f.read()
 
-def test_sample_part1():
+
+def test_sample_part1() -> None:
     assert DayRunner.part1(get_data()) == 11
 
-def test_sample_part2():
+
+def test_sample_part2() -> None:
     assert DayRunner.part2(get_data()) == 31