diff --git a/Gemfile b/Gemfile
index 69c8bef..11de40d 100644
--- a/Gemfile
+++ b/Gemfile
@@ -8,7 +8,7 @@ gem 'rails', '~> 5.2.2'
 # Use mysql as the database for Active Record
 gem 'mysql2', '>= 0.4.4', '< 0.6.0'
 # Use Puma as the app server
-gem 'puma', '~> 3.12'
+gem 'puma', '~> 4.3'
 # Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
 gem 'jbuilder', '~> 2.5'
 gem 'devise'
diff --git a/Gemfile.lock b/Gemfile.lock
index 13fb18e..865a1d8 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -81,7 +81,9 @@ GEM
     marcel (0.3.3)
       mimemagic (~> 0.3.2)
     method_source (0.9.2)
-    mimemagic (0.3.4)
+    mimemagic (0.3.10)
+      nokogiri (~> 1)
+      rake
     mini_mime (1.0.2)
     mini_portile2 (2.4.0)
     minitest (5.14.0)
@@ -91,7 +93,8 @@ GEM
     nokogiri (1.10.8)
       mini_portile2 (~> 2.4.0)
     orm_adapter (0.5.0)
-    puma (3.12.4)
+    puma (4.3.11)
+      nio4r (~> 2.0)
     rack (2.1.2)
     rack-cors (1.1.1)
       rack (>= 2.0.0)
@@ -166,7 +169,7 @@ DEPENDENCIES
   jbuilder (~> 2.5)
   listen (>= 3.0.5, < 3.2)
   mysql2 (>= 0.4.4, < 0.6.0)
-  puma (~> 3.12)
+  puma (~> 4.3)
   rack-cors
   rails (~> 5.2.2)
   spring