diff --git a/Gemfile.lock b/Gemfile.lock
index 6e4383c..75cbec9 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -55,6 +55,7 @@ GEM
       coffee-script-source
       execjs
     coffee-script-source (1.9.1.1)
+    concurrent-ruby (1.1.5)
     connection_pool (2.2.0)
     debug_inspector (0.0.2)
     devise (3.5.1)
@@ -126,7 +127,7 @@ GEM
       pry (>= 0.9.10)
     quiet_assets (1.1.0)
       railties (>= 3.1, < 5.0)
-    rack (1.6.4)
+    rack (1.6.11)
     rack-cors (0.4.0)
     rack-test (0.6.3)
       rack (>= 1.0)
@@ -184,8 +185,9 @@ GEM
       redis-namespace (~> 1.5, >= 1.5.2)
     slop (3.6.0)
     spring (1.3.6)
-    sprockets (3.2.0)
-      rack (~> 1.0)
+    sprockets (3.7.2)
+      concurrent-ruby (~> 1.0)
+      rack (> 1, < 3)
     sprockets-rails (2.3.2)
       actionpack (>= 3.0)
       activesupport (>= 3.0)