diff --git a/Gemfile b/Gemfile
index a687c16..4cdb0be 100644
--- a/Gemfile
+++ b/Gemfile
@@ -8,7 +8,7 @@ gem 'grape-api-generator'
 gem 'ipaddress'
 gem 'jbuilder', '~> 2.5'
 gem 'kaminari-grape', '~> 1.0', '>= 1.0.1'
-gem 'puma', '~> 3.11'
+gem 'puma', '~> 4.3'
 gem 'rails', '~> 5.2.4', '>= 5.2.4.5'
 gem 'sprockets', '~> 3.0'
 gem 'sqlite3', '~> 1.3.6'
diff --git a/Gemfile.lock b/Gemfile.lock
index e80ac9b..e129396 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -147,7 +147,8 @@ GEM
     parser (3.0.0.0)
       ast (~> 2.4.1)
     public_suffix (4.0.6)
-    puma (3.12.6)
+    puma (4.3.11)
+      nio4r (~> 2.0)
     racc (1.5.2)
     rack (2.2.3)
     rack-accept (0.4.5)
@@ -265,8 +266,8 @@ DEPENDENCIES
   jbuilder (~> 2.5)
   kaminari-grape (~> 1.0, >= 1.0.1)
   nokogiri (>= 1.11.0)
-  puma (~> 3.11)
-  rails (~> 5.2.2, >= 5.2.2.1)
+  puma (~> 4.3)
+  rails (~> 5.2.4, >= 5.2.4.5)
   rspec
   rspec-rails
   rubocop