diff --git a/Gemfile.lock b/Gemfile.lock
index c8882a66..a82ac221 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -139,7 +139,9 @@ GEM
     http_parser.rb (0.6.0)
     i18n (1.1.0)
       concurrent-ruby (~> 1.0)
-    icalendar (2.4.1)
+    icalendar (2.5.0)
+      ice_cube (~> 0.16)
+    ice_cube (0.16.3)
     io-like (0.3.0)
     jquery-rails (4.3.3)
       rails-dom-testing (>= 1, < 3)