diff --git a/Gemfile b/Gemfile
index 3376fc3..568c584 100644
--- a/Gemfile
+++ b/Gemfile
@@ -8,7 +8,7 @@ gem 'rails', '~> 5.2.3'
 # Use postgresql as the database for Active Record
 gem 'pg', '>= 0.18', '< 2.0'
 # 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/Gemfile.lock b/Gemfile.lock
index 1989461..107365e 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -83,6 +83,7 @@ GEM
       railties (>= 4.2.0)
     faker (2.7.0)
       i18n (>= 1.6, < 1.8)
+    ffi (1.11.2)
     ffi (1.11.2-x64-mingw32)
     figaro (1.1.1)
       thor (~> 0.14)
@@ -106,16 +107,23 @@ GEM
     marcel (0.3.3)
       mimemagic (~> 0.3.2)
     method_source (0.9.2)
-    mimemagic (0.3.3)
+    mimemagic (0.3.10)
+      nokogiri (~> 1)
+      rake
     mini_mime (1.0.2)
     mini_portile2 (2.4.0)
     minitest (5.13.0)
+    msgpack (1.3.1)
     msgpack (1.3.1-x64-mingw32)
     nio4r (2.5.2)
+    nokogiri (1.10.5)
+      mini_portile2 (~> 2.4.0)
     nokogiri (1.10.5-x64-mingw32)
       mini_portile2 (~> 2.4.0)
+    pg (1.1.4)
     pg (1.1.4-x64-mingw32)
-    puma (3.12.1)
+    puma (4.3.8)
+      nio4r (~> 2.0)
     rack (2.0.7)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
@@ -209,6 +217,7 @@ GEM
     websocket-extensions (0.1.4)
 
 PLATFORMS
+  ruby
   x64-mingw32
 
 DEPENDENCIES
@@ -224,7 +233,7 @@ DEPENDENCIES
   jquery-rails
   jquery-ui-rails
   pg (>= 0.18, < 2.0)
-  puma (~> 3.11)
+  puma (~> 4.3)
   rails (~> 5.2.3)
   rails-autocomplete
   rails-controller-testing