diff --git a/fluent-plugin-kubernetes-sumologic/Gemfile.lock b/fluent-plugin-kubernetes-sumologic/Gemfile.lock
index 2bb7290..76263cf 100644
--- a/fluent-plugin-kubernetes-sumologic/Gemfile.lock
+++ b/fluent-plugin-kubernetes-sumologic/Gemfile.lock
@@ -10,8 +10,9 @@ GEM
   specs:
     addressable (2.8.5)
       public_suffix (>= 2.0.2, < 6.0)
-    codecov (0.6.0)
-      simplecov (>= 0.15, < 0.22)
+    codecov (0.2.12)
+      json
+      simplecov
     concurrent-ruby (1.1.10)
     cool.io (1.7.1)
     crack (0.4.5)
@@ -32,6 +33,7 @@ GEM
     hashdiff (1.0.1)
     http_parser.rb (0.8.0)
     httpclient (2.8.3)
+    json (2.6.3)
     msgpack (1.5.1)
     power_assert (2.0.3)
     public_suffix (5.0.3)
@@ -40,7 +42,7 @@ GEM
     serverengine (2.3.2)
       sigdump (~> 0.2.2)
     sigdump (0.2.5)
-    simplecov (0.21.2)
+    simplecov (0.22.0)
       docile (~> 1.1)
       simplecov-html (~> 0.11)
       simplecov_json_formatter (~> 0.1)