diff --git a/fluentd/Gemfile.lock b/fluentd/Gemfile.lock
index e6b5658..4bf888a 100644
--- a/fluentd/Gemfile.lock
+++ b/fluentd/Gemfile.lock
@@ -1,8 +1,8 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    addressable (2.7.0)
-      public_suffix (>= 2.0.2, < 5.0)
+    addressable (2.8.1)
+      public_suffix (>= 2.0.2, < 6.0)
     concurrent-ruby (1.1.6)
     cool.io (1.6.0)
     domain_name (0.5.20190701)
@@ -99,7 +99,7 @@ GEM
     oj (3.8.1)
     prometheus-client (0.9.0)
       quantile (~> 0.2.1)
-    public_suffix (4.0.5)
+    public_suffix (5.0.0)
     quantile (0.2.1)
     rake (13.0.1)
     recursive-open-struct (1.1.1)