diff --git a/Gemfile.lock b/Gemfile.lock
index c065e29..5875992 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -81,7 +81,7 @@ GEM
       coffee-script-source
       execjs
     coffee-script-source (1.12.2)
-    concurrent-ruby (1.0.5)
+    concurrent-ruby (1.1.6)
     connection_pool (2.2.2)
     crass (1.0.3)
     debug_inspector (0.0.3)
@@ -348,7 +348,7 @@ GEM
     pusher-client (0.6.2)
       json
       websocket (~> 1.0)
-    rack (2.0.4)
+    rack (2.2.2)
     rack-test (0.8.3)
       rack (>= 1.0, < 3)
     rails (5.1.5)
@@ -444,7 +444,7 @@ GEM
     spring-watcher-listen (2.0.1)
       listen (>= 2.7, < 4.0)
       spring (>= 1.2, < 3.0)
-    sprockets (3.7.1)
+    sprockets (3.7.2)
       concurrent-ruby (~> 1.0)
       rack (> 1, < 3)
     sprockets-rails (3.2.1)