diff --git a/README.rst b/README.rst
index c699a68d..3be0a844 100644
--- a/README.rst
+++ b/README.rst
@@ -11,7 +11,7 @@ files.
 :Code: https://github.com/collective/icalendar
 :Mailing list: https://github.com/collective/icalendar/issues
 :Dependencies: `python-dateutil`_ and `pytz`_.
-:Compatible with: Python 2.7 and 3.4+
+:Compatible with: Python 2.7 & 3.4 untested; 3.5+, Pypy2 and Pypy3 tested
 :License: `BSD`_
 
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