diff --git a/Gemfile.lock b/Gemfile.lock
index 336e821..320ad9e 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -24,6 +24,7 @@ GEM
     builder (3.2.2)
     byebug (9.0.6)
     coderay (1.1.1)
+    concurrent-ruby (1.1.9)
     coveralls (0.8.16)
       json (>= 1.8, < 3)
       simplecov (~> 0.12.0)
@@ -31,7 +32,8 @@ GEM
       thor (~> 0.19.1)
       tins (>= 1.6.0, < 2)
     docile (1.1.5)
-    i18n (0.7.0)
+    i18n (0.9.5)
+      concurrent-ruby (~> 1.0)
     json (1.8.3)
     method_source (0.8.2)
     minitest (5.10.1)