diff --git a/requirements.txt b/requirements.txt
index eaf685a..a44fbb4 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,2 +1,3 @@
-icalendar
-BeautifulSoup4
\ No newline at end of file
+icalendar>=4.0.3
+BeautifulSoup4>=4.6.3
+requests>=2.20.1
\ No newline at end of file