diff --git a/CMakeLists.txt b/CMakeLists.txt
index 3dd30784f..947a79be5 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -87,6 +87,8 @@ if(BUILD_TESTING)
             ${CMAKE_CURRENT_SOURCE_DIR}/tools/tests/test_stubgen.py)
         add_test(NAME debt_split COMMAND ${Python3_EXECUTABLE}
             ${CMAKE_CURRENT_SOURCE_DIR}/tools/tests/test_debt_split.py)
+        add_test(NAME stubgen_stdout_newlines COMMAND ${Python3_EXECUTABLE}
+            ${CMAKE_CURRENT_SOURCE_DIR}/tools/tests/test_stubgen_stdout_newlines.py)
         add_test(NAME hardware_oracle COMMAND ${Python3_EXECUTABLE}
             ${CMAKE_CURRENT_SOURCE_DIR}/tools/hw-oracle/test_hw_oracle.py)
         add_test(NAME pr_overlap_exports COMMAND ${Python3_EXECUTABLE}
diff --git a/tools/stubgen.py b/tools/stubgen.py
index 492f485b5..444820d64 100644
--- a/tools/stubgen.py
+++ b/tools/stubgen.py
@@ -211,6 +211,7 @@ def main(argv=None):
     ap.add_argument("--td-out", required=False, default=None, help="output file for TechnicalDebt lines, which go in docs/dev/debt/MODULE.md, default stderr when code uses stdout, otherwise stdout")
     ap.add_argument("--td-only", action="store_true", help="print only TechnicalDebt lines, no code")
     args = ap.parse_args(argv)
+    sys.stdout.reconfigure(encoding="utf-8", newline="\n")
     try:
         if not args.td_only and args.out and args.td_out and same_file(args.out, args.td_out):
             ap.error("--out and --td-out must name different files")
diff --git a/tools/tests/test_stubgen_stdout_newlines.py b/tools/tests/test_stubgen_stdout_newlines.py
new file mode 100644
index 000000000..93b49efe1
--- /dev/null
+++ b/tools/tests/test_stubgen_stdout_newlines.py
@@ -0,0 +1,33 @@
+from pathlib import Path
+import subprocess
+import sys
+import tempfile
+import unittest
+
+tools = Path(__file__).resolve().parents[1]
+
+
+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")
+            return subprocess.run(
+                [sys.executable, str(tools / "stubgen.py"), "--module", "libkernel", "--nids", str(nids)] + list(extra),
+                capture_output=True,
+                check=True,
+            )
+
+    def test_code_on_stdout_uses_lf(self):
+        result = self.run_stubgen()
+        self.assertIn(b"\n", result.stdout)
+        self.assertNotIn(b"\r\n", result.stdout)
+
+    def test_td_only_on_stdout_uses_lf(self):
+        result = self.run_stubgen("--td-only")
+        self.assertIn(b"\n", result.stdout)
+        self.assertNotIn(b"\r\n", result.stdout)
+
+
+if __name__ == "__main__":
+    unittest.main()