diff --git a/.gitattributes b/.gitattributes
index 27d14cb..418e35c 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -1 +1,2 @@
 *m4n100k0p100t3000_cr_lf.inp -text
+*.test text eol=lf
diff --git a/.github/workflows/moocore.yml b/.github/workflows/moocore.yml
index 0387791..046073a 100644
--- a/.github/workflows/moocore.yml
+++ b/.github/workflows/moocore.yml
@@ -101,3 +101,38 @@ jobs:
           name: failed-tests-${{ matrix.os }}-${{ matrix.cc }}-${{ github.run_id }}
           path: failed-test-outputs/
           if-no-files-found: ignore
+
+  test-windows:
+    name: Run testsuite on Windows (MSYS2)
+    runs-on: windows-latest
+    env:
+      PYTHONIOENCODING: utf-8
+    defaults:
+      run:
+        shell: msys2 {0}
+
+    steps:
+      - name: Checkout moocore
+        uses: actions/checkout@v6
+        with:
+          repository: multi-objective/moocore
+          sparse-checkout: c
+
+      - name: Checkout testsuite
+        uses: actions/checkout@v6
+        with:
+          path: testsuite
+
+      - uses: msys2/setup-msys2@v2
+        with:
+          msystem: UCRT64
+          install: >-
+            make
+            xz
+            mingw-w64-ucrt-x86_64-gcc
+            mingw-w64-ucrt-x86_64-python
+            mingw-w64-ucrt-x86_64-python-joblib
+            mingw-w64-ucrt-x86_64-python-rich
+
+      - name: make test (DEBUG=1, -O3 -flto)
+        run: make -C c test OPT_CFLAGS="-O3 -flto"
diff --git a/regtest.py b/regtest.py
index 5b2bb05..7692291 100755
--- a/regtest.py
+++ b/regtest.py
@@ -1,5 +1,6 @@
 #!/usr/bin/env python3
 import os
+import pathlib
 import subprocess
 import sys
 import glob
@@ -121,9 +122,18 @@ def runcmd(command, cwd=None, env=None, outfile=subprocess.DEVNULL):
     full_env["ASAN_OPTIONS"] = ASAN_OPTIONS
     full_env["UBSAN_OPTIONS"] = UBSAN_OPTIONS
     stdout = outfile if outfile == subprocess.DEVNULL else subprocess.PIPE
+    bash = "bash"
+    if os.name == "nt":
+        msys_bash = (
+            pathlib.Path(sys.executable).parent.parent.parent
+            / "usr"
+            / "bin"
+            / "bash.exe"
+        )
+        if msys_bash.is_file():
+            bash = str(msys_bash)
     result = subprocess.run(
-        command,
-        shell=True,
+        [bash, "-c", command],
         env=full_env,
         check=False,
         cwd=cwd,
@@ -194,7 +204,13 @@ def main():
         print("\t for example:", sys.argv[0], "../bin/hv")
         sys.exit(1)
 
-    program = os.path.realpath(os.path.expanduser(sys.argv[1]))
+    program = pathlib.Path(os.path.realpath(os.path.expanduser(sys.argv[1]))).as_posix()
+    if (
+        os.name == "nt"
+        and not os.path.isfile(program)
+        and os.path.isfile(program + ".exe")
+    ):
+        program += ".exe"
     if not is_exe(program):
         print(f"error: '{program}' not found or not executable!")
         sys.exit(1)
@@ -214,7 +230,10 @@ def main():
 
     ntotal = len(tests)
     elapsed_time = time.time()
-    ok = Parallel(n_jobs=-2)(delayed(run_test)(test, program=program) for test in tests)
+    prefer = "threads" if os.name == "nt" else "processes"
+    ok = Parallel(n_jobs=-2, prefer=prefer)(
+        delayed(run_test)(test, program=program) for test in tests
+    )
     elapsed_time = time.time() - elapsed_time
     npassed = sum(ok)
     nfailed = ntotal - npassed