diff --git a/Gemfile.lock b/Gemfile.lock
index 691b5de..34ab7b4 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -48,7 +48,7 @@ GEM
     astrolabe (1.3.1)
       parser (~> 2.2)
     builder (3.2.2)
-    concurrent-ruby (1.0.2)
+    concurrent-ruby (1.1.5)
     crack (0.4.2)
       safe_yaml (~> 1.0.0)
     diff-lcs (1.2.5)
@@ -71,7 +71,7 @@ GEM
     parser (2.2.2.6)
       ast (>= 1.1, < 3.0)
     powerpack (0.1.1)
-    rack (1.6.4)
+    rack (1.6.11)
     rack-test (0.6.3)
       rack (>= 1.0)
     rails (4.2.6)
@@ -121,7 +121,7 @@ GEM
       ruby-progressbar (~> 1.4)
     ruby-progressbar (1.7.5)
     safe_yaml (1.0.4)
-    sprockets (3.6.0)
+    sprockets (3.7.2)
       concurrent-ruby (~> 1.0)
       rack (> 1, < 3)
     sprockets-rails (3.0.4)