diff --git a/.gitignore b/.gitignore
index 1d9210d1..a1dd7a12 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,6 +6,10 @@ __pycache__/
 # C extensions
 *.so
 
+# Cython
+*.c
+*.html
+
 # Distribution / packaging
 .Python
 build/
diff --git a/MANIFEST.in b/MANIFEST.in
index b5d987e1..850be450 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -1,7 +1,10 @@
 graft amulet_map_editor
-include README.md
 include requirements.txt
 include versioneer.py
 include icon.ico
 prune */__pycache__/*
 global-exclude *.py[cod]
+global-exclude *.c
+global-exclude *.html
+global-exclude *.log
+global-exclude *.md
diff --git a/pyproject.toml b/pyproject.toml
index 240f8759..704833eb 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -3,6 +3,7 @@ requires = [
     "setuptools >= 42",
     "wheel",
     "cython >= 0.29.13",
-    "versioneer-518"
+    "versioneer-518",
+    "numpy"
 ]
 build-backend = "setuptools.build_meta"
diff --git a/setup.py b/setup.py
index b0b9a60b..9fd4a434 100644
--- a/setup.py
+++ b/setup.py
@@ -1,9 +1,11 @@
 from typing import List
 from setuptools import setup, find_packages
+from Cython.Build import cythonize
 import os
 import glob
 import shutil
 import sys
+import numpy
 
 try:
     import versioneer
@@ -51,19 +53,18 @@ try:
 except:
     pass
 
-package_data = [
-    os.path.relpath(path, "amulet_map_editor")
-    for path in set(
-        glob.glob(os.path.join("amulet_map_editor", "**", "*.*"), recursive=True)
-    )
-    - set(
-        glob.glob(os.path.join("amulet_map_editor", "**", "*.py[cod]"), recursive=True)
-    )
-]
+if next(glob.iglob("amulet_map_editor/**/*.pyx", recursive=True), None):
+    # This throws an error if it does not match any files
+    ext = cythonize("amulet_map_editor/**/*.pyx")
+else:
+    ext = ()
+
 
 setup(
     install_requires=required_packages,
     packages=find_packages(),
-    package_data={"amulet_map_editor": package_data},
+    include_package_data=True,
     cmdclass=versioneer.get_cmdclass(),
+    ext_modules=ext,
+    include_dirs=[numpy.get_include()],
 )