diff --git a/Gemfile.lock b/Gemfile.lock
index aed2575..291e008 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -140,7 +140,7 @@ GEM
       mimemagic (~> 0.3.0)
       terrapin (~> 0.6.0)
     pg (0.21.0)
-    rack (1.6.8)
+    rack (1.6.12)
     rack-test (0.6.3)
       rack (>= 1.0)
     rails (4.2.6)