diff --git a/Gemfile.lock b/Gemfile.lock
index 13e8e39a86..4006c6e439 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -124,7 +124,7 @@ GEM
     http_parser.rb (0.8.0)
     i18n (1.6.0)
       concurrent-ruby (~> 1.0)
-    io-event (1.6.0)
+    io-event (1.6.4)
     json (2.7.2)
     kramdown (2.4.0)
       rexml