diff --git a/Gemfile b/Gemfile
old mode 100755
new mode 100644
index 8d1b4f9..d997158
--- a/Gemfile
+++ b/Gemfile
@@ -10,7 +10,7 @@ end
 gem 'rails', '~> 5.2.0'
 
 # Use Puma as the app server
-gem 'puma', '~> 3.11'
+gem 'puma', '~> 4.3'
 
 # Use Rack Timeout. Read more: https://github.com/heroku/rack-timeout
 gem 'rack-timeout', '~> 0.4'
diff --git a/Gemfile.lock b/Gemfile.lock
old mode 100755
new mode 100644
index f2ac418..1660951
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -137,7 +137,9 @@ GEM
     mime-types (3.1)
       mime-types-data (~> 3.2015)
     mime-types-data (3.2016.0521)
-    mimemagic (0.3.2)
+    mimemagic (0.3.10)
+      nokogiri (~> 1)
+      rake
     mini_mime (1.0.0)
     mini_portile2 (2.3.0)
     minitest (5.11.3)
@@ -160,7 +162,8 @@ GEM
     parallel (1.17.0)
     pg (1.0.0)
     popper_js (1.14.3)
-    puma (3.12.0)
+    puma (4.3.12)
+      nio4r (~> 2.0)
     rack (2.0.5)
     rack-protection (2.0.3)
       rack
@@ -306,7 +309,7 @@ DEPENDENCIES
   paperclip
   parallel
   pg (~> 1.0)
-  puma (~> 3.11)
+  puma (~> 4.3)
   rack-timeout (~> 0.4)
   rails (~> 5.2.0)
   rails4-autocomplete