diff --git a/Gemfile b/Gemfile
index cf5415e..0d0090d 100644
--- a/Gemfile
+++ b/Gemfile
@@ -11,7 +11,7 @@ gem 'rails', '~> 5.0.2'
 # Use postgresql as the database for Active Record
 gem 'pg', '~> 0.18'
 # Use Puma as the app server
-gem 'puma', '~> 3.0'
+gem 'puma', '~> 3.12', '>= 3.12.6'
 # Use Figaro as the environment variables manager
 gem 'figaro'
 # Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
diff --git a/Gemfile.lock b/Gemfile.lock
index 6ed555b..3d5f51d 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -84,7 +84,7 @@ GEM
       ast (~> 2.2)
     pg (0.19.0)
     powerpack (0.1.1)
-    puma (3.7.1)
+    puma (3.12.6)
     rack (2.0.1)
     rack-test (0.6.3)
       rack (>= 1.0)
@@ -182,7 +182,7 @@ DEPENDENCIES
   figaro
   listen (~> 3.0.5)
   pg (~> 0.18)
-  puma (~> 3.0)
+  puma (~> 3.12, >= 3.12.6)
   rails (~> 5.0.2)
   rspec-rails (~> 3.5)
   rubocop (~> 0.47.1)
@@ -194,4 +194,4 @@ DEPENDENCIES
   tzinfo-data
 
 BUNDLED WITH
-   1.14.4
+   1.17.3