diff --git a/Gemfile b/Gemfile
index 23571f0..b97bcb3 100644
--- a/Gemfile
+++ b/Gemfile
@@ -8,7 +8,7 @@ gem 'rails', '~> 5.2.1'
 # Use postgreSQL as the database for Active Record
 gem 'pg'
 # 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 781da4b..67116bb 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -191,7 +191,9 @@ GEM
     mime-types (3.2.2)
       mime-types-data (~> 3.2015)
     mime-types-data (3.2018.0812)
-    mimemagic (0.3.3)
+    mimemagic (0.3.10)
+      nokogiri (~> 1)
+      rake
     mini_magick (4.9.2)
     mini_mime (1.0.1)
     mini_portile2 (2.4.0)
@@ -211,7 +213,8 @@ GEM
     pg (1.1.4-x64-mingw32)
     popper_js (1.14.5)
     public_suffix (3.0.3)
-    puma (3.12.0)
+    puma (4.3.12)
+      nio4r (~> 2.0)
     rack (2.0.6)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
@@ -371,7 +374,7 @@ DEPENDENCIES
   particles-js-rails (~> 2.0)
   pg
   popper_js (~> 1.14)
-  puma (~> 3.11)
+  puma (~> 4.3)
   rails (~> 5.2.1)
   rails-autocomplete
   rails-controller-testing