diff --git a/setup.py b/setup.py
index e7dc009311450c1b8c866f75425f6977480dec48..742ad725555674b5d62f034ba2850b379f7a1f18 100644
--- a/setup.py
+++ b/setup.py
@@ -9,7 +9,7 @@ setup(
     author="Autistici/Inventati",
     author_email="info@autistici.org",
     url="https://git.autistici.org/ai3/tools/webdav-server",
-    install_requires=["wsgidav>=3"],
+    install_requires=["flup", "wsgidav>=3"],
     setup_requires=[],
     packages=find_packages(),
     package_data={},