diff --git a/requirements.txt b/requirements.txt
index 6a4dfca..f2a6b77 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,5 @@
 click==6.6
-Flask==0.11.1
+Flask==1.0
 icalendar==3.10
 itsdangerous==0.24
 Jinja2==2.8