diff --git a/Gemfile.lock b/Gemfile.lock
index 51fa53f0c..64beb9534 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -4,6 +4,7 @@ GEM
     addressable (2.5.2)
       public_suffix (>= 2.0.2, < 4.0)
     colorator (1.1.0)
+    concurrent-ruby (1.1.10)
     faraday (0.13.1)
       multipart-post (>= 1.2, < 3)
     ffi (1.9.18)
@@ -67,9 +68,8 @@ GEM
       addressable (>= 2.3.5, < 2.6)
       faraday (~> 0.8, < 1.0)
     subexec (0.2.3)
-    thread_safe (0.3.6)
-    tzinfo (1.2.3)
-      thread_safe (~> 0.1)
+    tzinfo (2.0.5)
+      concurrent-ruby (~> 1.0)
     tzinfo-data (1.2017.2)
       tzinfo (>= 1.0.0)
     wdm (0.1.1)