diff --git a/Gemfile b/Gemfile
index 9067966..32fb491 100644
--- a/Gemfile
+++ b/Gemfile
@@ -6,7 +6,7 @@ ruby '2.5.3'
 gem 'rails', '~> 5.2.2'
 gem 'pg', '>= 0.18', '< 2.0'
 # gem 'sqlite3'
-gem 'puma', '~> 3.11'
+gem 'puma', '~> 4.3'
 gem 'sass-rails', '~> 5.0'
 gem 'uglifier', '>= 1.3.0'
 gem 'coffee-rails', '~> 4.2'
diff --git a/Gemfile.lock b/Gemfile.lock
index def262e..c629527 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -106,7 +106,9 @@ GEM
     mime-types (3.3.1)
       mime-types-data (~> 3.2015)
     mime-types-data (3.2019.1009)
-    mimemagic (0.3.3)
+    mimemagic (0.3.10)
+      nokogiri (~> 1)
+      rake
     mini_mime (1.0.2)
     mini_portile2 (2.4.0)
     minitest (5.14.0)
@@ -116,7 +118,8 @@ GEM
     nokogiri (1.10.7)
       mini_portile2 (~> 2.4.0)
     pg (1.2.2)
-    puma (3.12.2)
+    puma (4.3.12)
+      nio4r (~> 2.0)
     rack (2.1.1)
     rack-cors (1.1.1)
       rack (>= 2.0.0)
@@ -229,7 +232,7 @@ DEPENDENCIES
   listen (>= 3.0.5, < 3.2)
   loofah (~> 2.3, >= 2.3.1)
   pg (>= 0.18, < 2.0)
-  puma (~> 3.11)
+  puma (~> 4.3)
   rack-cors
   rails (~> 5.2.2)
   rbnacl