diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 378afb51..fb1aa64c 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -22,10 +22,11 @@ jobs:
     - run: nox --session mypy-${{matrix.python-version}}
 
   test:
-    runs-on: ubuntu-latest
+    runs-on: ${{matrix.os}}
     strategy:
       matrix:
         python-version: ['3.7', '3.8', '3.9', '3.10', '3.11', '3.12']
+        os: [ubuntu-latest, windows-latest]
     steps:
     - uses: actions/checkout@v3
     - uses: actions/setup-python@v4
@@ -42,7 +43,7 @@ jobs:
       run: |
         poetry install
         poetry run coverage combine
-        mv .coverage .coverage.${{ matrix.python-version }}
+        mv .coverage .coverage.${{ matrix.python-version }}.${{matrix.os}}
 
     - name: Upload coverage data
       uses: actions/upload-artifact@v3
@@ -71,6 +72,7 @@ jobs:
       env:
         TOP: ${{github.workspace}}
       run: |
+        rm .coverage.*.windows-latest
         pip install coverage
         coverage combine
         coverage
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index b6b7dee2..d57cd56a 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -70,7 +70,7 @@ repos:
     stages:
     - commit-msg
   repo: https://github.com/commitizen-tools/commitizen
-  rev: 3.12.0
+  rev: v3.12.0
 
 
 - repo: https://github.com/PyCQA/docformatter
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3cdeffb8..8fbae2a8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,9 @@
+## v0.6.1 (2024-01-28)
+
+### Fix
+
+- use utf-8 encoding to read and write source files
+
 ## v0.6.0 (2023-12-10)
 
 ### Feat
diff --git a/inline_snapshot/__init__.py b/inline_snapshot/__init__.py
index c1b85b8b..8206cb32 100644
--- a/inline_snapshot/__init__.py
+++ b/inline_snapshot/__init__.py
@@ -4,4 +4,4 @@
 
 __all__ = ["snapshot", "external", "outsource"]
 
-__version__ = "0.6.0"
+__version__ = "0.6.1"
diff --git a/inline_snapshot/_config.py b/inline_snapshot/_config.py
index 551ef392..1b53567b 100644
--- a/inline_snapshot/_config.py
+++ b/inline_snapshot/_config.py
@@ -16,7 +16,7 @@ def read_config(path: Path) -> Config:
     if not path.exists():
         return Config()
 
-    data = toml.loads(path.read_text())
+    data = toml.loads(path.read_text("utf-8"))
 
     result = Config()
 
diff --git a/inline_snapshot/_external.py b/inline_snapshot/_external.py
index 9ba1a32d..0051147b 100644
--- a/inline_snapshot/_external.py
+++ b/inline_snapshot/_external.py
@@ -21,7 +21,8 @@ def _ensure_directory(self):
         gitignore = self.directory / ".gitignore"
         if not gitignore.exists():
             gitignore.write_text(
-                "# ignore all snapshots which are not refered in the source\n*-new.*\n"
+                "# ignore all snapshots which are not refered in the source\n*-new.*\n",
+                "utf-8",
             )
 
     def save(self, name, data):
diff --git a/inline_snapshot/_find_external.py b/inline_snapshot/_find_external.py
index 1306e3ec..e5e044a0 100644
--- a/inline_snapshot/_find_external.py
+++ b/inline_snapshot/_find_external.py
@@ -54,7 +54,7 @@ def used_externals_in(source) -> Set[str]:
 def used_externals() -> Set[str]:
     result = set()
     for filename in _inline_snapshot._files_with_snapshots:
-        result |= used_externals_in(pathlib.Path(filename).read_text())
+        result |= used_externals_in(pathlib.Path(filename).read_text("utf-8"))
 
     return result
 
diff --git a/inline_snapshot/_rewrite_code.py b/inline_snapshot/_rewrite_code.py
index 615b8708..0ebae3bd 100644
--- a/inline_snapshot/_rewrite_code.py
+++ b/inline_snapshot/_rewrite_code.py
@@ -145,7 +145,7 @@ def new_code(self):
         for lhs, rhs in pairwise(replacements):
             assert lhs.range.end <= rhs.range.start
 
-        code = self.filename.read_text()
+        code = self.filename.read_text("utf-8")
 
         is_formatted = code == format_code(code, self.filename)
 
diff --git a/pyproject.toml b/pyproject.toml
index 4282c7b9..0d6d3380 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -49,7 +49,7 @@ license = "MIT"
 name = "inline-snapshot"
 readme = "README.md"
 repository = "https://github.com/15r10nk/inline-snapshots"
-version = "0.6.0"
+version = "0.6.1"
 
 [tool.poetry.dependencies]
 asttokens = ">=2.0.5"
diff --git a/tests/conftest.py b/tests/conftest.py
index 06f53c40..999c7eeb 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -4,6 +4,7 @@
 import traceback
 from dataclasses import dataclass
 from dataclasses import field
+from pathlib import Path
 from typing import Set
 
 import black
@@ -61,12 +62,13 @@ def run(self, *flags):
             flags = Flags({*flags})
 
             nonlocal filecount
-            filename = tmp_path / f"test_{filecount}.py"
+            filename: Path = tmp_path / f"test_{filecount}.py"
             filecount += 1
 
             prefix = """\"\"\"
 PYTEST_DONT_REWRITE
 \"\"\"
+# äöß 🐍
 from inline_snapshot import snapshot
 from inline_snapshot import external
 from inline_snapshot import outsource
@@ -74,7 +76,7 @@ def run(self, *flags):
 """
             source = prefix + textwrap.dedent(self.source)
 
-            filename.write_text(source)
+            filename.write_text(source, "utf-8")
 
             print()
             print(f'run: inline-snapshot={",".join(flags.to_set())}')
@@ -91,7 +93,7 @@ def run(self, *flags):
                     error = False
 
                     try:
-                        exec(compile(filename.read_text(), filename, "exec"))
+                        exec(compile(filename.read_text("utf-8"), filename, "exec"))
                     except AssertionError:
                         traceback.print_exc()
                         error = True
@@ -110,7 +112,7 @@ def run(self, *flags):
 
                     recorder.fix_all(tags=["inline_snapshot"])
 
-            source = filename.read_text()[len(prefix) :]
+            source = filename.read_text("utf-8")[len(prefix) :]
             print("output:")
             print(textwrap.indent(source, " |", lambda line: True).rstrip())
             print("reported_flags:", snapshot_flags)
@@ -172,13 +174,17 @@ def project(pytester):
     class Project:
         def setup(self, source: str):
             self.header = """\
+# äöß 🐍
 from inline_snapshot import snapshot
 from inline_snapshot import outsource
 """
             if "# no imports" in source:
-                self.header = ""
+                self.header = """\
+# äöß 🐍
+"""
             else:
                 self.header = """\
+# äöß 🐍
 from inline_snapshot import snapshot
 from inline_snapshot import outsource
 """
@@ -189,23 +195,23 @@ def setup(self, source: str):
             source = header + source
             print("write code:")
             print(source)
-            self._filename.write_text(source)
+            self._filename.write_text(source, "utf-8")
 
         @property
         def _filename(self):
             return pytester.path / "test_file.py"
 
         def is_formatted(self):
-            code = self._filename.read_text()
+            code = self._filename.read_text("utf-8")
             return code == format_code(code, self._filename)
 
         def format(self):
             self._filename.write_text(
-                format_code(self._filename.read_text(), self._filename)
+                format_code(self._filename.read_text("utf-8"), self._filename), "utf-8"
             )
 
         def pyproject(self, source):
-            (pytester.path / "pyproject.toml").write_text(source)
+            (pytester.path / "pyproject.toml").write_text(source, "utf-8")
 
         def storage(self):
             return sorted(
@@ -216,8 +222,8 @@ def storage(self):
 
         @property
         def source(self):
-            assert self._filename.read_text()[: len(self.header)] == self.header
-            return self._filename.read_text()[len(self.header) :].lstrip()
+            assert self._filename.read_text("utf-8")[: len(self.header)] == self.header
+            return self._filename.read_text("utf-8")[len(self.header) :].lstrip()
 
         def run(self, *args):
             cache = pytester.path / "__pycache__"
diff --git a/tests/test_docs.py b/tests/test_docs.py
index e59c7fa0..e033a774 100644
--- a/tests/test_docs.py
+++ b/tests/test_docs.py
@@ -30,7 +30,7 @@ def test_docs(project, file, subtests):
 
     header = re.compile("<!-- inline-snapshot:(.*)-->")
 
-    text = file.read_text()
+    text = file.read_text("utf-8")
     new_lines = []
     block_lines = []
     options = set()
@@ -118,4 +118,4 @@ def test_docs(project, file, subtests):
             new_lines.append(line)
 
     if inline_snapshot._inline_snapshot._update_flags.fix:  # pragma: no cover
-        file.write_text("\n".join(new_lines) + "\n")
+        file.write_text("\n".join(new_lines) + "\n", "utf-8")
diff --git a/tests/test_external.py b/tests/test_external.py
index e0dd94ac..ea48f44e 100644
--- a/tests/test_external.py
+++ b/tests/test_external.py
@@ -323,13 +323,14 @@ def test_ensure_imports(tmp_path):
         """\
 from os import environ
 from os import getcwd
-"""
+""",
+        "utf-8",
     )
 
     with apply_changes():
         ensure_import(file, {"os": ["chdir", "environ"]})
 
-    assert file.read_text() == snapshot(
+    assert file.read_text("utf-8") == snapshot(
         """\
 from os import environ
 from os import getcwd
@@ -344,13 +345,14 @@ def test_ensure_imports_with_comment(tmp_path):
     file.write_text(
         """\
 from os import environ # comment
-"""
+""",
+        "utf-8",
     )
 
     with apply_changes():
         ensure_import(file, {"os": ["chdir"]})
 
-    assert file.read_text() == snapshot(
+    assert file.read_text("utf-8") == snapshot(
         """\
 from os import environ # comment
 
diff --git a/tests/test_rewrite_code.py b/tests/test_rewrite_code.py
index 9a79aebc..b4bddcc7 100644
--- a/tests/test_rewrite_code.py
+++ b/tests/test_rewrite_code.py
@@ -29,7 +29,8 @@ def test_rewrite(tmp_path):
 12345
 12345
 12345
-"""
+""",
+        "utf-8",
     )
 
     with ChangeRecorder().activate() as recorder:
@@ -43,7 +44,7 @@ def test_rewrite(tmp_path):
         recorder.fix_all()
 
     assert (
-        file.read_text()
+        file.read_text("utf-8")
         == """
 12a45
 1245