diff --git a/qsimcirq/py.typed b/qsimcirq/py.typed
new file mode 100644
index 000000000..d3245e747
--- /dev/null
+++ b/qsimcirq/py.typed
@@ -0,0 +1 @@
+# Marker file for PEP 561. This package uses inline types.
diff --git a/setup.py b/setup.py
index 4ab2b0028..da9c84851 100644
--- a/setup.py
+++ b/setup.py
@@ -81,7 +81,7 @@ def build_extension(self, ext):
     version=__version__,
     author='Vamsi Krishna Devabathini',
     author_email='devabathini92@gmail.com',
-    python_requires=('>=3.3.0'),
+    python_requires='>=3.3.0',
     install_requires=requirements,
     license='Apache 2',
     description=description,
@@ -90,4 +90,6 @@ def build_extension(self, ext):
     ext_modules=[CMakeExtension('qsimcirq/qsim')],
     cmdclass=dict(build_ext=CMakeBuild),
     zip_safe=False,
-    packages=['qsimcirq'])
+    packages=['qsimcirq'],
+    package_data={'qsimcirq': ['py.typed']},
+)