diff --git a/Gemfile.lock b/Gemfile.lock
index abbaf8458cf49..977815ff06618 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -64,6 +64,7 @@ GEM
       timers (~> 4.0.0)
     certified (1.0.0)
     coderay (1.1.0)
+    concurrent-ruby (1.1.10)
     connection_pool (2.2.0)
     crass (1.0.1)
     daemons (1.2.2)
@@ -123,7 +124,8 @@ GEM
     hiredis (0.6.0)
     hitimes (1.2.2)
     htmlentities (4.3.3)
-    i18n (0.7.0)
+    i18n (0.9.5)
+      concurrent-ruby (~> 1.0)
     image_optim (0.20.2)
       exifr (~> 1.1, >= 1.1.3)
       fspath (~> 2.1)