diff --git a/myapp/Gemfile b/myapp/Gemfile
index 263e5ed..8095de1 100644
--- a/myapp/Gemfile
+++ b/myapp/Gemfile
@@ -9,7 +9,7 @@ gem 'rails', '~> 5.2.0'
 # gem 'sqlite3'
 gem 'pg', '~> 1.0'
 # Use Puma as the app server
-gem 'puma', '~> 3.11'
+gem 'puma', '~> 4.3'
 # Use SCSS for stylesheets
 gem 'sass-rails', '~> 5.0'
 # Use Uglifier as compressor for JavaScript assets
diff --git a/myapp/Gemfile.lock b/myapp/Gemfile.lock
index 9386d8f..1e1c5ac 100644
--- a/myapp/Gemfile.lock
+++ b/myapp/Gemfile.lock
@@ -97,7 +97,9 @@ GEM
     marcel (0.3.3)
       mimemagic (~> 0.3.2)
     method_source (1.0.0)
-    mimemagic (0.3.5)
+    mimemagic (0.3.10)
+      nokogiri (~> 1)
+      rake
     mini_mime (1.0.2)
     mini_portile2 (2.4.0)
     minitest (5.14.1)
@@ -108,7 +110,8 @@ GEM
     orm_adapter (0.5.0)
     pg (1.2.3)
     public_suffix (4.0.5)
-    puma (3.12.6)
+    puma (4.3.12)
+      nio4r (~> 2.0)
     rack (2.2.3)
     rack-proxy (0.6.5)
       rack
@@ -230,7 +233,7 @@ DEPENDENCIES
   jbuilder (~> 2.5)
   listen (>= 3.0.5, < 3.2)
   pg (~> 1.0)
-  puma (~> 3.11)
+  puma (~> 4.3)
   rails (~> 5.2.0)
   redis (~> 4.0)
   rspec-rails (~> 3.8)