diff --git a/setup.py b/setup.py
index d34eb82..74e1c07 100644
--- a/setup.py
+++ b/setup.py
@@ -31,7 +31,7 @@ def _get_portpy_photon_version():
     author='Gourav Jhanwar, Mojtaba Tefagh, Vicki Taasti, Seppo Tuomaala, Saad Nadeem, Masoud Zarepisheh',
     author_email="jhanwarg@mskcc.struct, mtefagh@acm.struct, vicki.taasti@maastro.nl, tuomaals@mskcc.struct, nadeems@mskcc.struct, zarepism@mskcc.struct",
     description='First open-source radiation treatment planning system in Python',
-    long_description=open('README.md').read(),
+    long_description=open('README.md', encoding='utf-8').read(),
     long_description_content_type="text/markdown",
     python_requires='>=3.7',
     include_package_data=True,