diff --git a/Gemfile.lock b/Gemfile.lock
index 099b4bd..c5e4933 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -116,8 +116,7 @@ GEM
       coderay (~> 1.1.0)
       method_source (~> 0.8.1)
       slop (~> 3.4)
-    puma (2.11.3)
-      rack (>= 1.1, < 2.0)
+    puma (2.12.0)
     rack (1.6.4)
     rack-pjax (0.8.0)
       nokogiri (~> 1.5)