diff --git a/Gemfile b/Gemfile
old mode 100755
new mode 100644
index 0b5cbe6..82cdae9
--- a/Gemfile
+++ b/Gemfile
@@ -6,7 +6,7 @@ ruby '2.6.3'
 gem 'active_model_serializers', '~> 0.10.6'
 gem 'bcrypt', '~> 3.1.11'
 gem 'pg', '~> 0.21'
-gem 'puma', '~> 3.11.2'
+gem 'puma', '~> 4.3.12'
 gem 'rack-cors', '~> 1.0.2', require: 'rack/cors'
 gem 'rails', '~> 5.2.3'
 
diff --git a/Gemfile.lock b/Gemfile.lock
old mode 100755
new mode 100644
index ed00b3d..718d9b9
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -81,7 +81,9 @@ 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_mime (1.0.2)
     mini_portile2 (2.4.0)
     minitest (5.11.3)
@@ -101,7 +103,8 @@ GEM
       pry (~> 0.10)
     pry-rails (0.3.9)
       pry (>= 0.10.4)
-    puma (3.11.4)
+    puma (4.3.12)
+      nio4r (~> 2.0)
     rack (2.0.7)
     rack-cors (1.0.3)
     rack-test (1.1.0)
@@ -199,7 +202,7 @@ DEPENDENCIES
   pry (~> 0.11.3)
   pry-byebug (~> 3.6.0)
   pry-rails (~> 0.3.6)
-  puma (~> 3.11.2)
+  puma (~> 4.3.12)
   rack-cors (~> 1.0.2)
   rails (~> 5.2.3)
   rails_12factor (~> 0.0.3)