diff --git a/fluent-plugin-protobuf/Gemfile.lock b/fluent-plugin-protobuf/Gemfile.lock
index 6e285e7..560c690 100644
--- a/fluent-plugin-protobuf/Gemfile.lock
+++ b/fluent-plugin-protobuf/Gemfile.lock
@@ -27,7 +27,7 @@ GEM
     http_parser.rb (0.8.0)
     msgpack (1.6.0)
     power_assert (2.0.3)
-    rake (13.2.0)
+    rake (13.2.1)
     serverengine (2.3.2)
       sigdump (~> 0.2.2)
     sigdump (0.2.5)