diff --git a/egs/ljspeech/TTS/matcha/monotonic_align/setup.py b/egs/ljspeech/TTS/matcha/monotonic_align/setup.py
index df26c633e..0c5c57070 100644
--- a/egs/ljspeech/TTS/matcha/monotonic_align/setup.py
+++ b/egs/ljspeech/TTS/matcha/monotonic_align/setup.py
@@ -1,12 +1,30 @@
 # Copied from
 # https://github.com/shivammehta25/Matcha-TTS/blob/main/matcha/utils/monotonic_align/setup.py
-from distutils.core import setup
-
-import numpy
 from Cython.Build import cythonize
+from setuptools import Extension, setup
+from setuptools.command.build_ext import build_ext as _build_ext
 
+
+class build_ext(_build_ext):
+    """Overwrite build_ext."""
+
+    def finalize_options(self):
+        """Prevent numpy from thinking it is still in its setup process."""
+        _build_ext.finalize_options(self)
+        __builtins__.__NUMPY_SETUP__ = False
+        import numpy
+
+        self.include_dirs.append(numpy.get_include())
+
+
+exts = [
+    Extension(
+        name="core",
+        sources=["core.pyx"],
+    )
+]
 setup(
     name="monotonic_align",
-    ext_modules=cythonize("core.pyx"),
-    include_dirs=[numpy.get_include()],
+    ext_modules=cythonize(exts, language_level=3),
+    cmdclass={"build_ext": build_ext},
 )