diff --git a/Gemfile b/Gemfile
index 6814f70..3dff0f2 100644
--- a/Gemfile
+++ b/Gemfile
@@ -11,7 +11,7 @@ gem 'rails', '~> 5.1.7'
 # Use postgresql as the database for Active Record
 gem 'pg', '>= 0.18', '< 2.0'
 # Use Puma as the app server
-gem 'puma', '~> 3.7'
+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 e693a26..3d9cc1f 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -41,13 +41,13 @@ GEM
     addressable (2.7.0)
       public_suffix (>= 2.0.2, < 5.0)
     arel (8.0.0)
-    autoprefixer-rails (9.6.5)
-      execjs
+    autoprefixer-rails (10.4.2.0)
+      execjs (~> 2)
     bcrypt (3.1.13)
     bindex (0.8.1)
-    bootstrap-sass (3.3.7)
+    bootstrap-sass (3.4.1)
       autoprefixer-rails (>= 5.2.1)
-      sass (>= 3.3.4)
+      sassc (>= 2.0.0)
     bootstrap_form (4.3.0)
       actionpack (>= 5.0)
       activemodel (>= 5.0)
@@ -124,7 +124,8 @@ GEM
       cliver (~> 0.3.1)
       websocket-driver (>= 0.2.0)
     public_suffix (4.0.1)
-    puma (3.12.1)
+    puma (4.3.12)
+      nio4r (~> 2.0)
     rack (2.0.7)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
@@ -193,6 +194,8 @@ GEM
       sprockets (>= 2.8, < 4.0)
       sprockets-rails (>= 2.0, < 4.0)
       tilt (>= 1.1, < 3)
+    sassc (2.4.0)
+      ffi (~> 1.9)
     selenium-webdriver (3.142.6)
       childprocess (>= 0.5, < 4.0)
       rubyzip (>= 1.2.2)
@@ -235,7 +238,7 @@ PLATFORMS
   ruby
 
 DEPENDENCIES
-  bootstrap-sass (~> 3.3.6)
+  bootstrap-sass (~> 3.4.1)
   bootstrap_form
   byebug
   capybara (>= 2.15)
@@ -250,7 +253,7 @@ DEPENDENCIES
   listen (>= 3.0.5, < 3.2)
   pg (>= 0.18, < 2.0)
   poltergeist
-  puma (~> 3.7)
+  puma (~> 4.3)
   rails (~> 5.1.7)
   rails-controller-testing
   rspec-rails (~> 3.6)