diff --git a/Gemfile b/Gemfile
old mode 100755
new mode 100644
index 944952c..c122c2a
--- a/Gemfile
+++ b/Gemfile
@@ -11,7 +11,7 @@ gem 'rails', '~> 5.2'
 # 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
old mode 100755
new mode 100644
index 9f0ab03..1c3f544
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -97,7 +97,9 @@ 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_magick (4.9.3)
     mini_mime (1.0.1)
     mini_portile2 (2.4.0)
@@ -107,7 +109,8 @@ GEM
     nokogiri (1.10.1)
       mini_portile2 (~> 2.4.0)
     pg (1.1.4)
-    puma (3.12.0)
+    puma (4.3.12)
+      nio4r (~> 2.0)
     rack (2.0.6)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
@@ -194,7 +197,7 @@ DEPENDENCIES
   listen (>= 3.0.5, < 3.2)
   mini_magick
   pg (>= 0.18, < 2.0)
-  puma (~> 3.7)
+  puma (~> 4.3)
   rails (~> 5.2)
   sass-rails (~> 5.0)
   spring