diff --git a/setup.py b/setup.py
index ea2b417c..46244414 100755
--- a/setup.py
+++ b/setup.py
@@ -138,7 +138,9 @@ setup(
     scripts=['manage.py'],
     include_package_data=True,
     install_requires=[
-        'caldav',
+        'caldav == 0.11.0',
+        'icalendar == 4.0.3',
+        'recurring-ical-events == 2.0.1',
         'django >= 3.2, <3.3',
         'django-model-utils<4.3',
         'requests',