diff --git a/MeikoKuraya/rails_tutorial/Gemfile b/MeikoKuraya/rails_tutorial/Gemfile
index c8dfedf..dfdfec5 100644
--- a/MeikoKuraya/rails_tutorial/Gemfile
+++ b/MeikoKuraya/rails_tutorial/Gemfile
@@ -1,7 +1,7 @@
 source 'https://rubygems.org'
 
 gem 'rails',        '5.1.4'
-gem 'puma',         '4.3.9'
+gem 'puma',         '4.3.11'
 gem 'sass-rails',   '5.0.6'
 gem 'uglifier',     '3.2.0'
 gem 'coffee-rails', '4.2.2'
diff --git a/MeikoKuraya/rails_tutorial/Gemfile.lock b/MeikoKuraya/rails_tutorial/Gemfile.lock
index 02b00eb..22e6bf1 100644
--- a/MeikoKuraya/rails_tutorial/Gemfile.lock
+++ b/MeikoKuraya/rails_tutorial/Gemfile.lock
@@ -84,7 +84,7 @@ GEM
       mini_portile2 (~> 2.6.1)
       racc (~> 1.4)
     pg (0.20.0)
-    puma (4.3.9)
+    puma (4.3.11)
       nio4r (~> 2.0)
     racc (1.5.2)
     rack (2.2.3)
@@ -171,7 +171,7 @@ DEPENDENCIES
   jquery-rails (= 4.3.1)
   listen (= 3.1.5)
   pg (= 0.20.0)
-  puma (= 4.3.9)
+  puma (= 4.3.11)
   rails (= 5.1.4)
   sass-rails (= 5.0.6)
   spring (= 2.0.2)