diff --git a/Gemfile b/Gemfile
index d339208..4470daf 100644
--- a/Gemfile
+++ b/Gemfile
@@ -8,7 +8,7 @@ end
 
 gem 'rails', '~> 5.1.7'
 gem 'mysql2', '>= 0.3.18', '< 0.5'
-gem 'puma', '~> 3.0'
+gem 'puma', '~> 3.12'
 gem 'sqlite3'
 gem 'pg'
 
diff --git a/Gemfile.lock b/Gemfile.lock
index cea9329..e865431 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -69,7 +69,7 @@ GEM
     nokogiri (1.10.7)
       mini_portile2 (~> 2.4.0)
     pg (1.1.4)
-    puma (3.12.2)
+    puma (3.12.6)
     rack (2.0.8)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
@@ -129,7 +129,7 @@ DEPENDENCIES
   listen (~> 3.0.5)
   mysql2 (>= 0.3.18, < 0.5)
   pg
-  puma (~> 3.0)
+  puma (~> 3.12)
   rails (~> 5.1.7)
   spring
   spring-watcher-listen (~> 2.0.0)