diff --git a/Gemfile b/Gemfile
index 2ab5f3b..fa8aa00 100644
--- a/Gemfile
+++ b/Gemfile
@@ -8,7 +8,7 @@ gem 'rails', '~> 6.0.0'
 # Use mysql as the database for Active Record
 gem 'mysql2', '>= 0.4.4'
 # Use Puma as the app server
-gem 'puma', '~> 3.11'
+gem 'puma', '~> 4.3'
 # Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
 # gem 'jbuilder', '~> 2.7'
 # Use Redis adapter to run Action Cable in production
diff --git a/Gemfile.lock b/Gemfile.lock
index 0486efb..321ca89 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -79,12 +79,17 @@ GEM
     mini_mime (1.0.2)
     mini_portile2 (2.4.0)
     minitest (5.11.3)
+    msgpack (1.3.1)
     msgpack (1.3.1-x64-mingw32)
+    mysql2 (0.5.2)
     mysql2 (0.5.2-x64-mingw32)
     nio4r (2.5.1)
+    nokogiri (1.10.4)
+      mini_portile2 (~> 2.4.0)
     nokogiri (1.10.4-x64-mingw32)
       mini_portile2 (~> 2.4.0)
-    puma (3.12.1)
+    puma (4.3.11)
+      nio4r (~> 2.0)
     rack (2.0.7)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
@@ -135,12 +140,13 @@ GEM
 
 PLATFORMS
   x64-mingw32
+  x86_64-linux
 
 DEPENDENCIES
   bootsnap (>= 1.4.2)
   byebug
   mysql2 (>= 0.4.4)
-  puma (~> 3.11)
+  puma (~> 4.3)
   rails (~> 6.0.0)
   tzinfo-data