diff --git a/.github/workflows/test.yaml b/.github/workflows/test.yaml
index 7492898..3f7de14 100644
--- a/.github/workflows/test.yaml
+++ b/.github/workflows/test.yaml
@@ -8,7 +8,13 @@ on:
 
 jobs:
   unit:
-    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, windows-latest, macos-latest]
+        python-version: [3.12, 3.13]
+        dependency-mode: [lowest-direct, highest]
+    runs-on: ${{ matrix.os }}
     steps:
     - uses: actions/checkout@v4
     - name: Install uv
@@ -18,12 +24,13 @@ jobs:
     - name: Set up Python
       uses: actions/setup-python@v5
       with:
-        python-version-file: pyproject.toml
+        python-version: ${{ matrix.python-version }}
     - name: Install the project
-      run: uv sync --only-dev
+      run: uv sync --only-dev --resolution=${{ matrix.dependency-mode }}
     - name: Run tests
       id: run-tests
-      run: >
+      shell: bash
+      run: |
         uv run pytest \
           --junitxml=pytest.xml \
           --cov-report=term-missing:skip-covered \
diff --git a/tests/unit/test_reader.py b/tests/unit/test_reader.py
index 87c23c2..16b9358 100644
--- a/tests/unit/test_reader.py
+++ b/tests/unit/test_reader.py
@@ -1,6 +1,7 @@
 """Test cases for reader.py functions."""
 
 import pathlib
+import re
 
 import pandas as pd
 import pytest
@@ -33,7 +34,7 @@ def test_parse_filename_valid(sample_data: pathlib.Path) -> None:
 )
 def test_parse_filename_invalid(invalid_filename: str) -> None:
     """Test that invalid filenames raise a ValueError."""
-    filename = invalid_filename.replace("[", "\\[").replace("]", "\\]")
+    filename = re.escape(invalid_filename)
     with pytest.raises(
         ValueError,
         match=f"Filename does not match expected pattern: {filename}",
@@ -69,6 +70,6 @@ def test_load_spiral(sample_data: pathlib.Path) -> None:
 def test_load_spiral_invalid_extension(sample_data: pathlib.Path) -> None:
     """Test that loading a non-CSV file raises an error."""
     invalid_file = sample_data.with_suffix(".txt")
-    filename = invalid_file.as_posix().replace("[", "\\[").replace("]", "\\]")
+    filename = re.escape(str(invalid_file))
     with pytest.raises(IOError, match=f"Error reading file {filename}"):
         reader.load_spiral(invalid_file)