diff --git a/ruby-parser/Gemfile b/ruby-parser/Gemfile
index 7510d0b..8f73308 100644
--- a/ruby-parser/Gemfile
+++ b/ruby-parser/Gemfile
@@ -5,7 +5,7 @@ ruby '2.4.4'
 
 gem 'rails', '~> 5.2.3'
 gem 'mysql2', '>= 0.4.4', '< 0.6.0'
-gem 'puma', '~> 3.11'
+gem 'puma', '~> 3.12'
 gem 'bootsnap', '>= 1.1.0', require: false
 
 group :development, :test do
diff --git a/ruby-parser/Gemfile.lock b/ruby-parser/Gemfile.lock
index 0c648f1..c194397 100644
--- a/ruby-parser/Gemfile.lock
+++ b/ruby-parser/Gemfile.lock
@@ -86,7 +86,7 @@ GEM
     nio4r (2.4.0)
     nokogiri (1.10.3)
       mini_portile2 (~> 2.4.0)
-    puma (3.12.1)
+    puma (3.12.3)
     rack (2.0.7)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
@@ -169,7 +169,7 @@ DEPENDENCIES
   faker
   listen (>= 3.0.5, < 3.2)
   mysql2 (>= 0.4.4, < 0.6.0)
-  puma (~> 3.11)
+  puma (~> 3.12)
   rails (~> 5.2.3)
   rspec-rails (~> 3.5)
   shoulda-matchers (~> 3.1)