diff --git a/tools/tests/test_pr_overlap_encoding.py b/tools/tests/test_pr_overlap_encoding.py
index 73082080d6..c8c04aff4d 100644
--- a/tools/tests/test_pr_overlap_encoding.py
+++ b/tools/tests/test_pr_overlap_encoding.py
@@ -26,7 +26,7 @@ def simulated_cp1252():
         wrapper = io.TextIOWrapper
 
         def fake_wrapper(buffer, encoding=None, *args, **kwargs):
-            if encoding == "locale":
+            if encoding in (None, "locale"):
                 encoding = "cp1252"
             return wrapper(buffer, encoding=encoding, *args, **kwargs)
 
diff --git a/tools/tests/test_stubgen_stdout_newlines.py b/tools/tests/test_stubgen_stdout_newlines.py
index 93b49efe1c..110719d87b 100644
--- a/tools/tests/test_stubgen_stdout_newlines.py
+++ b/tools/tests/test_stubgen_stdout_newlines.py
@@ -11,7 +11,7 @@ class StubgenStdoutNewlineTests(unittest.TestCase):
     def run_stubgen(self, *extra):
         with tempfile.TemporaryDirectory() as d:
             nids = Path(d) / "nids.txt"
-            nids.write_text("AC1FtjqMCL0\n", encoding="utf-8", newline="\n")
+            nids.write_bytes(b"AC1FtjqMCL0\n")
             return subprocess.run(
                 [sys.executable, str(tools / "stubgen.py"), "--module", "libkernel", "--nids", str(nids)] + list(extra),
                 capture_output=True,