diff --git a/Gemfile.lock b/Gemfile.lock
index fefa97ac9..94c8e0268 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -62,6 +62,7 @@ GEM
       net-ssh (>= 2.0.14)
       net-ssh-gateway (>= 1.1.0)
     coderay (1.1.0)
+    concurrent-ruby (1.1.7)
     crack (0.4.2)
       safe_yaml (~> 1.0.0)
     debug_inspector (0.0.2)
@@ -126,7 +127,7 @@ GEM
       coderay (~> 1.0)
       method_source (~> 0.8)
       slop (~> 3.4)
-    rack (1.6.2)
+    rack (1.6.13)
     rack-contrib (1.1.0)
       rack (>= 0.9.1)
     rack-protection (1.5.2)
@@ -209,8 +210,9 @@ GEM
       tilt (~> 1.3, >= 1.3.4)
     slack-notifier (1.0.0)
     slop (3.6.0)
-    sprockets (3.0.3)
-      rack (~> 1.0)
+    sprockets (3.7.2)
+      concurrent-ruby (~> 1.0)
+      rack (> 1, < 3)
     sprockets-rails (2.2.4)
       actionpack (>= 3.0)
       activesupport (>= 3.0)